Circuit quantum electrodynamics is one of the most promising platforms for efficient quantum simulation and computation. In recent groundbreaking experiments, the immense flexibility of superconducting microwave resonators was utilized to realize hyperbolic lattices that emulate quantum physics in negatively curved space. Here we investigate experimentally feasible settings in which a few superconducting qubits are coupled to a bath of photons evolving on the hyperbolic lattice. We compare our numerical results for finite lattices with analytical results for continuous hyperbolic space on the Poincar{\'e} disk. We find good agreement between the two descriptions in the long-wavelength regime. We show that photon-qubit bound states have a curvature-limited size. We propose to use a qubit as a local probe of the hyperbolic bath, for example, by measuring the relaxation dynamics of the qubit. We find that, although the boundary effects strongly impact the photonic density of states, the spectral density is well described by the continuum theory. We show that interactions between qubits are mediated by photons propagating along geodesics. We demonstrate that the photonic bath can give rise to geometrically frustrated hyperbolic quantum spin models with finite-range or exponentially decaying interaction.

}, doi = {10.1103/PhysRevLett.128.013601}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.128.013601}, author = {Bienias, Przemyslaw and Boettcher, Igor and Belyansky, Ron and Kollar, Alicia J. and Gorshkov, Alexey V.} } @article { WOS:000727004500001, title = {Dynamical evolution and decay of multi-charged quantum vortex in a Bose-Einstein condensate}, journal = {Laser Phys. Lett.}, volume = {19}, number = {1}, year = {2022}, month = {JAN}, publisher = {IOP Publishing Ltd}, type = {Article}, abstract = {We report the observation of the twisted decay of quadruply charged vortices taking place in an atomic Bose-Einstein condensate. Supporting numerical simulations show that the singly-charged vortices, which result from the decay of a multi-charged vortex, twist around intertwined in the shape of helical Kelvin waves.}, keywords = {Bose-Einstein condensates, Kelvin waves, multiply charged vortices}, issn = {1612-2011}, doi = {10.1088/1612-202X/ac3d24}, author = {Telles, G. D. and Tavares, P. E. S. and Fritsch, A. R. and Cidrim, A. and Bagnato, V. S.} } @article { WOS:000704382500004, title = {PyLCP: A Python package for computing laser cooling physics}, journal = {Comput. Phys. Commun.}, volume = {270}, year = {2022}, month = {JAN}, publisher = {ELSEVIER}, type = {Article}, abstract = {We present a Python object-oriented computer program for simulating various aspects of laser cooling physics. Our software is designed to be both easy to use and adaptable, allowing the user to specify the level structure, magnetic field profile, or the laser beams{\textquoteright} geometry, detuning, and intensity. The program contains three levels of approximation for the motion of the atom, applicable in different regimes offering cross checks for calculations and computational efficiency depending on the physical situation. We test the software by reproducing well-known phenomena, such as damped Rabi flopping, electromagnetically induced transparency, stimulated Raman adiabatic passage, and optical molasses. We also use our software package to quantitatively simulate recoil-limited magneto-optical traps, like those formed on the narrow S-1(0) -> P-3(1) transition in Sr-88 and Sr-87. (C) 2021 Published by Elsevier B.V.}, keywords = {atomic physics, laser cooling, python}, issn = {0010-4655}, doi = {10.1016/j.cpc.2021.108166}, author = {Eckel, Stephen and Barker, Daniel S. and Norrgard, Eric B. and Scherschligt, Julia} } @article { WOS:000680428500001, title = {Anomalies and unusual stability of multicomponent Luttinger liquids in Z(n) x Z(n) spin chains}, journal = {Phys. Rev. B}, volume = {104}, number = {4}, year = {2021}, month = {JUL 30}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study translationally invariant spin chains where each unit cell contains an n-state projective representation of a Z(n) x Z(n) internal symmetry, generalizing the spin-1/2 XYZ chain. Such spin chains possess a generalized Lieb-Schultz-Mattis (LSM) constraint, and we demonstrate that certain (n - 1)-component Luttinger liquids possess the correct anomalies to satisfy these LSM constraints. For n = 3, using both numerical and analytical approaches, we find that such spin chains with nearest-neighbor interactions appear to be gapless for a wide range of microscopic parameters and described by a two-component conformally invariant Luttinger liquid. This implies the emergence of n - 1 conserved U(1) charges from only discrete microscopic symmetries. Remarkably, the system remains gapless for an unusually large parameter regime despite the apparent existence of symmetryallowed relevant operators in the field theory. This suggests that either these spin chains have hidden conserved quantities not previously identified, or the parameters of the field theory are simply unusual due to frustration effects of the lattice Hamiltonian. We argue that similar features are expected to occur in (1) Z(n) x Z(n) symmetric chains for n odd and (2) S-n x Z(n) symmetric chains for all n > 2. Finally, we suggest the possibility of a lower bound growing with n on the minimum central charge of field theories that possess such LSM anomalies.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.104.045151}, author = {Alavirad, Yahya and Barkeshli, Maissam} } @article { WOS:000704665100001, title = {Asymmetric Blockade and Multiqubit Gates via Dipole-Dipole Interactions}, journal = {Phys. Rev. Lett.}, volume = {127}, number = {12}, year = {2021}, month = {SEP 17}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Because of their strong and tunable interactions, Rydberg atoms can be used to realize fast two-qubit entangling gates. We propose a generalization of a generic two-qubit Rydberg-blockade gate to multiqubit Rydberg-blockade gates that involve both many control qubits and many target qubits simultaneously. This is achieved by using strong microwave fields to dress nearby Rydberg states, leading to asymmetric blockade in which control-target interactions are much stronger than control-control and target-target interactions. The implementation of these multiqubit gates can drastically simplify both quantum algorithms and state preparation. To illustrate this, we show that a 25-atom Greenberger-Horne-Zeilinger state can be created using only three gates with an error of 5.8\%.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.127.120501}, author = {Young, Jeremy T. and Bienias, Przemyslaw and Belyansky, Ron and Kaufman, Adam M. and Gorshkov, V, Alexey} } @article {lee_bright_2021, title = {Bright {Telecom}-{Wavelength} {Single} {Photons} {Based} on a {Tapered} {Nanobeam}}, journal = {Nano Lett.}, volume = {21}, number = {1}, year = {2021}, note = {Place: 1155 16TH ST, NW, WASHINGTON, DC 20036 USA Publisher: AMER CHEMICAL SOC Type: Article}, month = {jan}, pages = {323{\textendash}329}, abstract = {Telecom-wavelength single photons are essential components for long-distance quantum networks. However, bright and pure single photon sources at telecom wavelengths remain challenging to achieve. Here, we demonstrate a bright telecom-wavelength single photon source based on a tapered nanobeam containing InAs/InP quantum dots. The tapered nanobeam enables directional and Gaussian-like far-field emission of the quantum dots. As a result, using above-band excitation we obtain an end-to-end brightness of 4.1 +/- 0.1\% and first-lens brightness of 27.0 +/- 0.1\% at the -1300 nm wavelength. Furthermore, we adopt quasi-resonant excitation to reduce both multiphoton emission and decoherence from unwanted charge carriers. As a result, we achieve a coherence time of 523 +/- 16 ps and postselected Hong-Ou-Mandel visibility of 0 .91 +/- 0.09 along with a comparable first-lens brightness of 21.0 +/- 0.1\%. These results represent a major step toward a practical fiber-based single photon source at telecom wavelengths for long-distance quantum networks.

}, keywords = {Quantum Dots, single photon sources, telecom wavelength, two-photon interference}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.0c03680}, author = {Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Harper, Samuel and Aghaeimeibodi, Shahriar and Richardson, Christopher J. K. and Waks, Edo} } @article { WOS:000652838200010, title = {Chiral Anomaly in Interacting Condensed Matter Systems}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {18}, year = {2021}, month = {MAY 7}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The chiral anomaly is a fundamental quantum mechanical phenomenon which is of great importance to both particle physics and condensed matter physics alike. In the context of QED, it manifests as the breaking of chiral symmetry in the presence of electromagnetic fields. It is also known that anomalous chiral symmetry breaking can occur through interactions alone, as is the case for interacting one-dimensional systems. In this Letter, we investigate the interplay between these two modes of anomalous chiral symmetry breaking in the context of interacting Weyl semimetals. Using Fujikawa{\textquoteright}s path integral method, we show that the chiral charge continuity equation is modified by the presence of interactions which can be viewed as including the effect of the electric and magnetic fields generated by the interacting quantum matter. This can be understood further using dimensional reduction and a Luttinger liquid description of the lowest Landau level. These effects manifest themselves in the nonlinear response of the system. In particular, we find an interaction-dependent density response due to a change in the magnetic field as well as a contribution to the nonequilibrium and inhomogeneous anomalous Hall response while preserving its equilibrium value.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.185303}, author = {Rylands, Colin and Parhizkar, Alireza and Burkov, Anton A. and Galitski, Victor} } @article {burenkov_coherent_2021, title = {Coherent optical processes with an all-optical atomic simulator}, journal = {Opt. Express}, volume = {29}, number = {1}, year = {2021}, note = {Place: 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA Publisher: OPTICAL SOC AMER Type: Article}, month = {jan}, pages = {330{\textendash}341}, abstract = {We show how novel photonic devices such as broadband quantum memory and efficient quantum frequency transduction can be implemented using three-wave mixing processes in a 1D array of nonlinear waveguides evanescently coupled to nearest neighbors. We do this using an analogy of an atom interacting with an external optical field using both classical and quantum models of the optical fields and adapting well-known coherent processes from atomic optics, such as electromagnetically induced transparency and stimulated Raman adiabatic passage to design. This approach allows the implementation of devices that are very difficult or impossible to implement by conventional techniques.

}, issn = {1094-4087}, doi = {10.1364/OE.415480}, author = {Burenkov, Ivan A. and Novikova, Irina and Tikhonova, Olga V and Polyakov, Sergey V} } @article {curtis_critical_2021, title = {Critical theory for the breakdown of photon blockade}, journal = {Phys. Rev. Res.}, volume = {3}, number = {2}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, abstract = {Photon blockade is the result of the interplay between the quantized nature of light and strong optical nonlinearities, whereby strong photon-photon repulsion prevents a quantum optical system from absorbing multiple photons. We theoretically study a single atom coupled to the light field, described by the resonantly driven Jaynes-Cummings model, in which case the photon blockade breaks down in a second-order phase transition at a critical drive strength. We show that this transition is associated to the spontaneous breaking of an antiunitary PT symmetry. Within a semiclassical approximation, we calculate the expectation values of observables in the steady state. We then move beyond the semiclassical approximation and approach the critical point from the disordered (blockaded) phase by reducing the Lindblad quantum master equation to a classical rate equation that we solve. The width of the steady-state distribution in Fock space is found to diverge as we approach the critical point with a simple power law, allowing us to calculate the critical scaling of steady-state observables without invoking mean-field theory. We propose a simple physical toy model for biased diffusion in the space of occupation numbers, which captures the universal properties of the steady state. We list several experimental platforms where this phenomenon may be observed.}, doi = {10.1103/PhysRevResearch.3.023062}, author = {Curtis, Jonathan B. and Boettcher, Igor and Young, Jeremy T. and Maghrebi, Mohammad F. and Carmichael, Howard and Gorshkov, V, Alexey and Foss-Feig, Michael} } @article {manjunath_crystalline_2021, title = {Crystalline gauge fields and quantized discrete geometric response for {Abelian} topological phases with lattice symmetry}, journal = {Phys. Rev. Res.}, volume = {3}, number = {1}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jan}, abstract = {Clean isotropic quantum Hall fluids in the continuum possess a host of symmetry-protected quantized invariants, such as the Hall conductivity, shift, and Hall viscosity. Here we develop a theory of symmetry-protected quantized invariants for topological phases defined on a lattice, where quantized invariants with no continuum analog can arise. We develop topological field theories using discrete crystalline gauge fields to fully characterize quantized invariants of (2 + 1)D Abelian topological orders with symmetry group G = U(1) x G(space), where G(space) consists of orientation-preserving space group symmetries on the lattice. We show how discrete rotational and translational symmetry fractionalization can be characterized by a discrete spin vector, a discrete torsion vector which has no analog in the continuum or in the absence of lattice rotation symmetry, and an area vector, which also has no analog in the continuum. The discrete torsion vector implies a type of crystal momentum fractionalization that is only nontrivial for two, three, and fourfold rotation symmetry. The quantized topological response theory includes a discrete version of the shift, which binds fractional charge to disclinations and corners, a fractionally quantized angular momentum of disclinations, rotationally symmetric fractional charge polarization and its angular momentum counterpart, constraints on charge and angular momentum per unit cell, and quantized momentum bound to dislocations and units of area. The fractionally quantized charge polarization, which is nontrivial only on a lattice with two, three, and fourfold rotation symmetry, implies a fractional charge bound to lattice dislocations and a fractional charge per unit length along the boundary. An important role is played by a finite group grading on Burgers vectors, which depends on the point group symmetry of the lattice.}, doi = {10.1103/PhysRevResearch.3.013040}, author = {Manjunath, Naren and Barkeshli, Maissam} } @article { WOS:000691406500003, title = {Demonstration of Shor Encoding on a Trapped-Ion Quantum Computer}, journal = {Phys. Rev. Appl.}, volume = {16}, number = {2}, year = {2021}, month = {AUG 30}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Fault-tolerant quantum error correction (QEC) is crucial for unlocking the true power of quantum computers. QEC codes use multiple physical qubits to encode a logical qubit, which is protected against errors at the physical qubit level. Here, we use a trapped-ion system to experimentally prepare m-qubit Greenberger-Horne-Zeilinger states and sample the measurement results to construct m x m logical states of the {[}{[}m(2), 1, m]] Shor code, up to m = 7. The synthetic logical fidelity shows how deeper encoding can compensate for additional gate errors in state preparation for larger logical states. However, the optimal code size depends on the physical error rate and we find that m = 5 has the best performance in our system. We further realize the direct logical encoding of the {[}{[}9, 1, 3]] Shor code on nine qubits in a 13-ion chain for comparison, with 98.8(1)\% and 98.5(1)\% fidelity for state vertical bar +/->(L), respectively.}, issn = {2331-7019}, doi = {10.1103/PhysRevApplied.16.024057}, author = {Nguyen, Nhung H. and Li, Muyuan and Green, Alaina M. and Alderete, C. Huerta and Zhu, Yingyue and Zhu, Daiwei and Brown, Kenneth R. and Linke, Norbert M.} } @article { WOS:000674685900002, title = {Development of Quantum Interconnects (QuICs) for Next-Generation Information Technologies}, journal = {PRX Quantum}, volume = {2}, number = {1}, year = {2021}, month = {FEB 24}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Just as {\textquoteleft}{\textquoteleft}classical{{\textquoteright}{\textquoteright}} information technology rests on a foundation built of interconnected information-processing systems, quantum information technology (QIT) must do the same. A critical component of such systems is the {\textquoteleft}{\textquoteleft}interconnect,{{\textquoteright}{\textquoteright}} a device or process that allows transfer of information between disparate physical media, for example, semiconductor electronics, individual atoms, light pulses in optical fiber, or microwave fields. While interconnects have been well engineered for decades in the realm of classical information technology, quantum interconnects (QuICs) present special challenges, as they must allow the transfer of fragile quantum states between different physical parts or degrees of freedom of the system. The diversity of QIT platforms (superconducting, atomic, solid-state color center, optical, etc.) that will form a {\textquoteleft}{\textquoteleft}quantum internet{{\textquoteright}{\textquoteright}} poses additional challenges. As quantum systems scale to larger size, the quantum interconnect bottleneck is imminent, and is emerging as a grand challenge for QIT. For these reasons, it is the position of the community represented by participants of the NSF workshop on {\textquoteleft}{\textquoteleft}Quantum Interconnects{{\textquoteright}{\textquoteright}} that accelerating QuIC research is crucial for sustained development of a national quantum science and technology program. Given the diversity of QIT platforms, materials used, applications, and infrastructure required, a convergent research program including partnership between academia, industry, and national laboratories is required.}, doi = {10.1103/PRXQuantum.2.017002}, author = {Awschalom, David and Berggren, Karl K. and Bernien, Hannes and Bhave, Sunil and Carr, Lincoln D. and Davids, Paul and Economou, Sophia E. and Englund, Dirk and Faraon, Andrei and Fejer, Martin and Guha, Saikat and Gustafsson, V, Martin and Hu, Evelyn and Jiang, Liang and Kim, Jungsang and Korzh, Boris and Kumar, Prem and Kwiat, Paul G. and Loncar, Marko and Lukin, Mikhail D. and Miller, David A. B. and Monroe, Christopher and Nam, Sae Woo and Narang, Prineha and Orcutt, Jason S. and Raymer, Michael G. and Safavi-Naeini, Amir H. and Spiropulu, Maria and Srinivasan, Kartik and Sun, Shuo and Vuckovic, Jelena and Waks, Edo and Walsworth, Ronald and Weiner, Andrew M. and Zhang, Zheshen} } @article {baldwin_distinct_2021, title = {Distinct critical behaviors from the same state in quantum spin and population dynamics perspectives}, journal = {Phys. Rev. E}, volume = {103}, number = {1}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jan}, abstract = {There is a deep connection between the ground states of transverse-field spin systems and the late-time distributions of evolving viral populations-within simple models, both are obtained from the principal eigen-vector of the same matrix. However, that vector is the wave-function amplitude in the quantum spin model, whereas it is the probability itself in the population model. We show that this seemingly minor difference has significant consequences: Phase transitions that are discontinuous in the spin system become continuous when viewed through the population perspective, and transitions that are continuous become governed by new critical exponents. We introduce a more general class of models that encompasses both cases and that can be solved exactly in a mean-field limit. Numerical results are also presented for a number of one-dimensional chains with power-law interactions. We see that well-worn spin models of quantum statistical mechanics can contain unexpected new physics and insights when treated as population-dynamical models and beyond, motivating further studies.}, issn = {2470-0045}, doi = {10.1103/PhysRevE.103.012106}, author = {Baldwin, C. L. and Shivam, S. and Sondhi, S. L. and Kardar, M.} } @article {21096, title = {Domain-wall confinement and dynamics in a quantum simulator}, journal = {Nat. Phys.}, year = {2021}, abstract = {Particles subject to confinement experience an attractive potential that increases without bound as they separate. A prominent example is colour confinement in particle physics, in which baryons and mesons are produced by quark confinement. Confinement can also occur in low-energy quantum many-body systems when elementary excitations are confined into bound quasiparticles. Here we report the observation of magnetic domain-wall confinement in interacting spin chains with a trapped-ion quantum simulator. By measuring how correlations spread, we show that confinement can suppress information propagation and thermalization in such many-body systems. We quantitatively determine the excitation energy of domain-wall bound states from the non-equilibrium quench dynamics. We also study the number of domain-wall excitations created for different quench parameters, in a regime that is difficult to model with classical computers. This work demonstrates the capability of quantum simulators for investigating high-energy physics phenomena, such as quark collision and string breaking. Long-range Ising interactions present in one-dimensional spin chains can induce a confining potential between pairs of domain walls, slowing down the thermalization of the system. This has now been observed in a trapped-ion quantum simulator.

}, issn = {1745-2473}, doi = {10.1038/s41567-021-01194-3}, author = {Tan, W. L. and Becker, P. and Liu, F. and Pagano, G. and Collins, K. S. and De, A. and Feng, L. and Kaplan, H. B. and Kyprianidis, A. and Lundgren, R. and Morong, W. and Whitsitt, S. and Gorshkov, A. V. and Monroe, C.} } @article { WOS:000661896800004, title = {Efficient Stabilized Two-Qubit Gates on a Trapped-Ion Quantum Computer}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {22}, year = {2021}, month = {JUN 4}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {In order to scale up quantum processors and achieve a quantum advantage, it is crucial to economize on the power requirement of two-qubit gates, make them robust to drift in experimental parameters, and shorten the gate times. Applicable to all quantum computer architectures whose two-qubit gates rely on phase-space closure, we present here a new gate-optimizing principle according to which negligible amounts of gate fidelity are traded for substantial savings in power, which, in turn, can be traded for substantial increases in gate speed and/or qubit connectivity. As a concrete example, we illustrate the method by constructing optimal pulses for entangling gates on a pair of ions within a trapped-ion chain, one of the leading quantum computing architectures. Our method is direct, noniterative, and linear, and, in some parameter regimes, constructs gate-steering pulses requiring up to an order of magnitude less power than the standard method. Additionally, our method provides increased robustness to mode drift. We verify the new trade-off principle experimentally on our trapped-ion quantum computer.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.220503}, author = {Blumel, Reinhold and Grzesiak, Nikodem and Nguyen, Nhung H. and Green, Alaina M. and Li, Ming and Maksymov, Andrii and Linke, Norbert M. and Nam, Yunseong} } @article { WOS:000647487800006, title = {Exact analytical treatment of multiqubit noisy dynamics in exchange-coupled semiconductor spin qubits}, journal = {Phys. Rev. B}, volume = {103}, number = {20}, year = {2021}, month = {MAY 3}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Charge noise remains the primary obstacle to the development of quantum information technologies with semiconductor spin qubits. We use an exact analytical calculation to determine the effects of quasistatic charge noise on a ring of three equally spaced exchange-coupled quantum dots. We calculate the disorder-averaged return probability from a specific initial state and use it to determine the coherence time T-2{*} and show that it depends on only the disorder strength and not the mean interaction strength. We also use a perturbative approach to investigate other arrangements of three or four qubits, finding that the return probability contains multiple oscillation frequencies. These oscillations decay in a Gaussian manner, determined by differences in energy levels of the Hamiltonian. We give quantitative values for gate times resulting in several target fidelities. We find that the decoherence time decreases with an increasing number of qubits. Our work provides useful analytical insight into the charge noise dynamics of coupled spin qubits.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.103.205402}, author = {Buterakos, Donovan and Das Sarma, Sankar} } @article {dehghani_extraction_2021, title = {Extraction of the many-body {Chern} number from a single wave function}, journal = {Phys. Rev. B}, volume = {103}, number = {7}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {feb}, abstract = {The quantized Hall conductivity of integer and fractional quantum Hall (IQH and FQH) states is directly related to a topological invariant, the many-body Chern number. The conventional calculation of this invariant in interacting systems requires a family of many-body wave functions parameterized by twist angles to calculate the Berry curvature. In this paper, we demonstrate how to extract the Chern number given a single many-body wave function, without knowledge of the Hamiltonian. For FQH states, our method requires one additional integer invariant as input: the number of 2 pi flux quanta, s, that must be inserted to obtain a topologically trivial excitation. As we discuss, s can be obtained in principle from the degenerate set of ground state wave functions on the torus, without knowledge of the Hamiltonian. We perform extensive numerical simulations involving IQH and FQH states to validate these methods.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.103.075102}, author = {Dehghani, Hossein and Cian, Ze-Pei and Hafezi, Mohammad and Barkeshli, Maissam} } @article {21316, title = {Fault-tolerant control of an error-corrected qubit}, journal = {Nature}, year = {2021}, abstract = {Quantum error correction protects fragile quantum information by encoding it into a larger quantum system1,2. These extra degrees of freedom enable the detection and correction of errors, but also increase the control complexity of the encoded logical qubit. Fault-tolerant circuits contain the spread of errors while controlling the logical qubit, and are essential for realizing error suppression in practice3,4,5,6. Although fault-tolerant design works in principle, it has not previously been demonstrated in an error-corrected physical system with native noise characteristics. Here we experimentally demonstrate fault-tolerant circuits for the\ preparation, measurement, rotation and stabilizer measurement of a Bacon{\textendash}Shor logical qubit using 13 trapped ion qubits. When we compare these fault-tolerant protocols to non-fault-tolerant protocols, we see significant reductions in the error rates of the logical primitives in the presence of noise. The result of fault-tolerant design is an average state preparation and measurement error of 0.6\ per cent and a Clifford gate error of 0.3\ per cent after offline error correction. In addition, we prepare magic states with fidelities that exceed the distillation threshold7, demonstrating all of the key single-qubit ingredients required for universal fault-tolerant control. These results demonstrate that fault-tolerant circuits enable highly accurate logical primitives in current quantum systems. With improved two-qubit gates and the use of intermediate measurements, a stabilized logical qubit can be achieved.

}, keywords = {error correction, Ion trap, quantum computing}, doi = {10.1038/s41586-021-03928-y}, url = {https://doi.org/10.1038/s41586-021-03928-y}, author = {Laird Egan and Dripto M. Debroy and Crystal Noel and Andrew Risinger and Daiwei Zhu and Debopriyo Biswas and Michael Newman and Muyuan Li and Kenneth R. Brown and Marko Cetina and Christopher Monroe} } @article {mueller_single-particle-like_2021, title = {From single-particle-like to interaction-mediated plasmonic resonances in graphene nanoantennas}, journal = {J. Appl. Phys.}, volume = {129}, number = {9}, year = {2021}, note = {Place: 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA Publisher: AMER INST PHYSICS Type: Article}, month = {mar}, abstract = {Plasmonic nanostructures attract tremendous attention as they confine electromagnetic fields well below the diffraction limit while simultaneously sustaining extreme local field enhancements. To fully exploit these properties, the identification and classification of resonances in such nanostructures is crucial. Recently, a novel figure of merit for resonance classification has been proposed [Muller et al., J. Phys. Chem. C 124, 24331-24343 (2020)] and its applicability was demonstrated mostly to toy model systems. This novel measure, the energy-based plasmonicity index (EPI), characterizes the nature of resonances in molecular nanostructures. The EPI distinguishes between either a single-particle-like or a plasmonic nature of resonances based on the energy space coherence dynamics of the excitation. To advance the further development of this newly established measure, we present here its exemplary application to characterize the resonances of graphene nanoantennas. In particular, we focus on resonances in a doped nanoantenna. The structure is of interest, as a consideration of the electron dynamics in real space might suggest a plasmonic nature of selected resonances in the low doping limit but our analysis reveals the opposite. We find that in the undoped and moderately doped nanoantenna, the EPI classifies all emerging resonances as predominantly single-particle-like, and only after doping the structure heavily, the EPI observes plasmonic response.}, issn = {0021-8979}, doi = {10.1063/5.0038883}, author = {Mueller, Marvin M. and Kosik, Miriam and Pelc, Marta and Bryant, Garnett W. and Ayuela, Andres and Rockstuhl, Carsten and Slowik, Karolina} } @article { WOS:000693643600008, title = {Frustration-induced anomalous transport and strong photon decay in waveguide QED}, journal = {Phys. Rev. Res.}, volume = {3}, number = {3}, year = {2021}, month = {SEP 7}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study the propagation of photons in a one-dimensional environment consisting of two noninteracting species of photons frustratingly coupled to a single spin 1/2. The ultrastrong frustrated coupling leads to an extreme mixing of the light and matter degrees of freedom, resulting in the disintegration of the spin and a breakdown of the {\textquoteleft}{\textquoteleft}dressed-spin,{{\textquoteright}{\textquoteright}} or polaron, description. Using a combination of numerical and analytical methods, we show that the elastic response becomes increasingly weak at the effective spin frequency, showing instead an increasingly strong and broadband response at higher energies. We also show that the photons can decay into multiple photons of smaller energies. The total probability of these inelastic processes can be as large as the total elastic scattering rate, or half of the total scattering rate, which is as large as it can be. The frustrated spin induces strong anisotropic photon-photon interactions that are dominated by interspecies interactions. Our results are relevant to state-of-the-art circuit and cavity quantum electrodynamics experiments.}, doi = {10.1103/PhysRevResearch.3.L032058}, author = {Belyansky, Ron and Whitsitt, Seth and Lundgren, Rex and Wang, Yidan and Vrajitoarea, Andrei and Houck, Andrew A. and Gorshkov, V, Alexey} } @article { WOS:000674695300001, title = {Geometrical Formalism for Dynamically Corrected Gates in Multiqubit Systems}, journal = {PRX Quantum}, volume = {2}, number = {1}, year = {2021}, month = {MAR 9}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The ability to perform gates in multiqubit systems that are robust to noise is of crucial importance for the advancement of quantum information technologies. However, finding control pulses that cancel noise while performing a gate is made difficult by the intractability of the time-dependent Schrodinger equation, especially in multiqubit systems. Here, we show that this issue can be sidestepped by using a formalism in which the cumulative error during a gate is represented geometrically as a curve in a multidimensional Euclidean space. Cancelation of noise errors to leading order corresponds to closure of the curve, a condition that can be satisfied without solving the Schrodinger equation. We develop and uncover general properties of this geometric formalism, and derive a recursion relation that maps control fields to curvatures for Hamiltonians of arbitrary dimension. We demonstrate the utility of the formalism by employing it to design pulses that simultaneously correct against both noise errors and crosstalk for two qubits coupled by an Ising interaction. We give examples both of a single-qubit rotation and a two-qubit maximally entangling gate. The results obtained in this example are relevant to both superconducting transmon qubits and semiconductor quantum-dot spin qubits. We propose this geometric formalism as a general technique for pulse-induced error suppression in quantum computing gate operations.}, doi = {10.1103/PRXQuantum.2.010341}, author = {Buterakos, Donovan and Das Sarma, Sankar and Barnes, Edwin} } @article {briles_hybrid_2021, title = {Hybrid {InP} and {SiN} integration of an octave-spanning frequency comb}, journal = {APL Phontonics}, volume = {6}, number = {2}, year = {2021}, note = {Place: 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA Publisher: AMER INST PHYSICS Type: Article}, month = {feb}, abstract = {Implementing optical-frequency combs with integrated photonics will enable wider use of precision timing signals. Here, we explore the generation of an octave-span, Kerr-microresonator frequency comb using hybrid integration of an InP distributed-feedback laser and a SiN photonic-integrated circuit. We demonstrate electrically pumped and fiber-packaged prototype systems, enabled by self-injection locking. This direct integration of a laser and a microresonator circuit without previously used intervening elements, such as optical modulators and isolators, necessitates understanding self-injection-locking dynamics with octave-span Kerr solitons. In particular, system architectures must adjust to the strong coupling of microresonator backscattering and laser-microresonator frequency detuning that we uncover here. Our work illustrates critical considerations toward realizing a self-referenced frequency comb with integrated photonics.}, issn = {2378-0967}, doi = {10.1063/5.0035452}, author = {Briles, Travis C. and Yu, Su-Peng and Chang, Lin and Xiang, Chao and Guo, Joel and Kinghorn, David and Moille, Gregory and Srinivasan, Kartik and Bowers, John E. and Papp, Scott B.} } @article { WOS:000652838500026, title = {Inelastic Scattering of a Photon by a Quantum Phase Slip}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {19}, year = {2021}, month = {MAY 12}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Spontaneous decay of a single photon is a notoriously inefficient process in nature irrespective of the frequency range. We report that a quantum phase-slip fluctuation in high-impedance super-conducting waveguides can split a single incident microwave photon into a large number of lower-energy photons with a near unit probability. The underlying inelastic photon-photon interaction has no analogs in nonlinear optics. Instead, the measured decay rates are explained without adjustable parameters in the framework of a new model of a quantum impurity in a Luttinger liquid. Our result connects circuit quantum electrodynamics to critical phenomena in two-dimensional boundary quantum field theories, important in the physics of strongly correlated systems. The photon lifetime data represent a rare example of verified and useful quantum many-body simulation.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.197701}, author = {Kuzmin, R. and Grabon, N. and Mehta, N. and Burshtein, A. and Goldstein, M. and Houzet, M. and Glazman, I, L. and Manucharyan, V. E.} } @article {21336, title = {Lieb-Robinson Light Cone for Power-Law Interactions}, journal = {Phys. Rev. Lett.}, volume = {127}, year = {2021}, month = {Oct}, pages = {160401}, abstract = {The Lieb-Robinson theorem states that information propagates with a finite velocity in quantum systems on a lattice with nearest-neighbor interactions. What are the speed limits on information propagation in quantum systems with power-law interactions, which decay as\ 1/rα\ at distance\ r? Here, we present a definitive answer to this question for all exponents\ α\>2d\ and all spatial dimensions\ d. Schematically, information takes time at least\ rmin{1,α-2d}\ to propagate a distance\ r. As recent state transfer protocols saturate this bound, our work closes a decades-long hunt for optimal Lieb-Robinson bounds on quantum information dynamics with power-law interactions.

}, doi = {10.1103/PhysRevLett.127.160401}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.127.160401}, author = {Tran, Minh C. and Guo, Andrew Y. and Baldwin, Christopher L. and Ehrenberg, Adam and Gorshkov, Alexey V. and Lucas, Andrew} } @article {wayne_low-noise_2021, title = {Low-noise photon counting above 100 x 10(6) counts per second with a high-efficiency reach-through single-photon avalanche diode system}, journal = {Appl. Phys. Lett.}, volume = {118}, number = {13}, year = {2021}, note = {Place: 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA Publisher: AMER INST PHYSICS Type: Article}, abstract = {We demonstrate a method that allows a high-efficiency single-photon-avalanche diode (SPAD) with a thick absorption region ({\textgreater}10 mu m) to count single photons at rates significantly higher than previously demonstrated. We apply large ({\textgreater}30V) AC bias gates to the SPAD at 1GHz and detect minute avalanches with a discrimination threshold of 5(1) mV by means of radio frequency interferometry. We measure a reduction by a factor of approximate to 500 in the average charge per avalanche when compared to operation in its traditional active-quenching module and a relative increase in {\textgreater}19\% in detection efficiency at 850nm. The reduction in charge strongly suppresses self-heating effects in the diode that can degrade performance at high avalanche rates. We show that the single-photon detection system maintains high efficiency at count rates exceeding 10(8) s(-1).}, issn = {0003-6951}, doi = {10.1063/5.0041984}, author = {Wayne, Michael A. and Bienfang, Joshua C. and Migdall, Alan L.} } @article {mcgehee_magneto-optical_2021, title = {Magneto-optical trapping using planar optics}, journal = {New J. Phys.}, volume = {23}, number = {1}, year = {2021}, note = {Place: TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND Publisher: IOP PUBLISHING LTD Type: Article}, month = {jan}, abstract = {Laser-cooled atoms are a key technology for many calibration-free measurement platforms-including clocks, gyroscopes, and gravimeters-and are a promising system for quantum networking and quantum computing. The optics and vacuum hardware required to prepare these gases are often bulky and not amenable to large-volume manufacturing, limiting the practical realization of devices benefiting from the properties of cold atoms. Planar, lithographically produced optics including photonic integrated circuits, optical metasurfaces (MSs), and gratings offer a pathway to develop chip-scale, manufacturable devices utilizing cold atoms. As a demonstration of this technology, we have realized laser cooling of atomic Rb in a grating-type magneto-optical trap (MOT) using planar optics for beam launching, beam shaping, and polarization control. Efficient use of available light is accomplished using MS-enabled beam shaping, and the performance of the planar optics MOT is competitive with Gaussian-beam illuminated grating MOTs.}, keywords = {laser cooling, metasurfaces, photonic integrated circuits}, issn = {1367-2630}, doi = {10.1088/1367-2630/abdce3}, author = {McGehee, William R. and Zhu, Wenqi and Barker, Daniel S. and Westly, Daron and Yulaev, Alexander and Klimov, Nikolai and Agrawal, Amit and Eckel, Stephen and Aksyuk, Vladimir and McClelland, Jabez J.} } @article {cian_many-body_2021, title = {Many-{Body} {Chern} {Number} from {Statistical} {Correlations} of {Randomized} {Measurements}}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {5}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {feb}, abstract = {One of the main topological invariants that characterizes several topologically ordered phases is the many-body Chern number (MBCN). Paradigmatic examples include several fractional quantum Hall phases, which are expected to be realized in different atomic and photonic quantum platforms in the near future. Experimental measurement and numerical computation of this invariant are conventionally based on the linear-response techniques that require having access to a family of states, as a function of an external parameter, which is not suitable for many quantum simulators. Here, we propose an ancilla-free experimental scheme for the measurement of this invariant, without requiring any knowledge of the Hamiltonian. Specifically, we use the statistical correlations of randomized measurements to infer the MBCN of a wave function. Remarkably, our results apply to disklike geometries that are more amenable to current quantum simulator architectures.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.050501}, author = {Cian, Ze-Pei and Dehghani, Hossein and Elben, Andreas and Vermersch, Benoit and Zhu, Guanyu and Barkeshli, Maissam and Zoller, Peter and Hafezi, Mohammad} } @article { WOS:000655878500007, title = {Many-body physics in small systems: Observing the onset and saturation of correlation in linear atomic chains}, journal = {Phys. Rev. B}, volume = {103}, number = {19}, year = {2021}, month = {MAY 20}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The exact study of small systems can guide us toward relevant measures for extracting information about many-body physics as we move to larger and more complex systems capable of quantum information processing or quantum analog simulation. We use exact diagonalization to study many electrons in short one-dimensional atom chains represented by long-range extended Hubbard-like models. We introduce a measure, the single-particle excitation content (SPEC) of an eigenstate and show that the functional dependence of the SPEC on the eigenstate number reveals the nature of the ground state (ordered phases), and the onset and saturation of correlation between the electrons as Coulomb interaction strength increases. We use this SPEC behavior to identify five regimes as interaction is increased: A noninteracting single-particle regime, a regime of perturbative Coulomb interaction in which the SPEC is a nearly universal function of eigenstate number, the onset and saturation of correlation, a regime of fully correlated states in which hopping is a perturbation, and the SPEC is a different universal function of state number and the regime of no hopping. In particular, the behavior of the SPEC shows that when electron-electron correlation plays a minor role, all of the lowest-energy eigenstates are made up primarily of single-particle excitations of the ground state, and as the Coulomb interaction increases, the lowest-energy eigenstates increasingly contain many-particle excitations. In addition, the SPEC highlights a fundamental distinct difference between a noninteracting system and one with minute very weak interactions. Although the SPEC is a quantity that can be calculated for small exactly diagonalizable systems, it guides our intuition for larger systems, suggesting the nature of excitations and their distribution in the spectrum. Thus, this function, such as correlation functions or order parameters, provides us with a window of intuition about the behavior of a physical system.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.103.195429}, author = {Townsend, Emily and Neuman, Tomas and Debrecht, Alex and Aizpurua, Javier and Bryant, Garnett W.} } @article {lavasani_measurement-induced_2021, title = {Measurement-induced topological entanglement transitions in symmetric random quantum circuits}, journal = {Nat. Phys.}, volume = {17}, number = {3}, year = {2021}, note = {Place: HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY Publisher: NATURE RESEARCH Type: Article}, month = {mar}, pages = {342+}, abstract = {Random quantum circuits, in which an array of qubits is subjected to a series of randomly chosen unitary operations, have provided key insights into the dynamics of many-body quantum entanglement. Recent work has shown that interleaving the unitary operations with single-qubit measurements can drive a transition between high- and low-entanglement phases. Here we study a class of symmetric random quantum circuits with two competing types of measurement in addition to unitary dynamics. We find a rich phase diagram involving robust symmetry-protected topological, trivial and volume law entangled phases, where the transitions are hidden to expectation values of any operator and are only apparent by averaging the entanglement entropy over quantum trajectories. In the absence of unitary dynamics, we find a purely measurement-induced critical point, which maps exactly to two copies of a classical two-dimensional percolation problem. Numerical simulations indicate that this transition is a tricritical point that splits into two critical lines in the presence of arbitrarily sparse unitary dynamics with an intervening volume law entangled phase. Our results show that measurements alone are sufficient to induce criticality and logarithmic entanglement scaling, and arbitrarily sparse unitary dynamics can be sufficient to stabilize volume law entangled phases in the presence of rapid, yet competing, measurements.}, issn = {1745-2473}, doi = {10.1038/s41567-020-01112-z}, author = {Lavasani, Ali and Alavirad, Yahya and Barkeshli, Maissam} } @article {carney_mechanical_2021, title = {Mechanical quantum sensing in the search for dark matter}, journal = {Quantum Sci. Technol.}, volume = {6}, number = {2}, year = {2021}, note = {Place: TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND Publisher: IOP PUBLISHING LTD Type: Article}, month = {apr}, abstract = {Numerous astrophysical and cosmological observations are best explained by the existence of dark matter, a mass density which interacts only very weakly with visible, baryonic matter. Searching for the extremely weak signals produced by this dark matter strongly motivate the development of new, ultra-sensitive detector technologies. Paradigmatic advances in the control and readout of massive mechanical systems, in both the classical and quantum regimes, have enabled unprecedented levels of sensitivity. In this white paper, we outline recent ideas in the potential use of a range of solid-state mechanical sensing technologies to aid in the search for dark matter in a number of energy scales and with a variety of coupling mechanisms.}, keywords = {dark matter, Optomechanics, quantum sensing, standard quantum limits}, issn = {2058-9565}, doi = {10.1088/2058-9565/abcfcd}, author = {Carney, D. and Krnjaic, G. and Moore, D. C. and Regal, C. A. and Afek, G. and Bhave, S. and Brubaker, B. and Corbitt, T. and Cripe, J. and Crisosto, N. and Geraci, A. and Ghosh, S. and Harris, J. G. E. and Hook, A. and Kolb, E. W. and Kunjummen, J. and Lang, R. F. and Li, T. and Lin, T. and Liu, Z. and Lykken, J. and Magrini, L. and Manley, J. and Matsumoto, N. and Monte, A. and Monteiro, F. and Purdy, T. and Riedel, C. J. and Singh, R. and Singh, S. and Sinha, K. and Taylor, J. M. and Qin, J. and Wilson, D. J. and Zhao, Y.} } @article {yang_momentum_2021, title = {Momentum space toroidal moment in a photonic metamaterial}, journal = {Nat. Commun.}, volume = {12}, number = {1}, year = {2021}, note = {Place: HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY Publisher: NATURE RESEARCH Type: Article}, month = {mar}, abstract = {Berry curvature, the counterpart of the magnetic field in the momentum space, plays a vital role in the transport of electrons in condensed matter physics. It also lays the foundation for the emerging field of topological physics. In the three-dimensional systems, much attention has been paid to Weyl points, which serve as sources and drains of Berry curvature. Here, we demonstrate a toroidal moment of Berry curvature with flux approaching to in judiciously engineered metamaterials. The Berry curvature exhibits a vortex-like configuration without any source and drain in the momentum space. Experimentally, the presence of Berry curvature toroid is confirmed by the observation of conical-frustum shaped domain-wall states at the interfaces formed by two metamaterials with opposite toroidal moments. The appearance of toroidal multipolar moments in electrodynamics interrogates the question for their existence in Berry curvature, which can be seen as the {\textquotedblleft}magnetic field{\textquotedblright} in the momentum space. Here, the authors observe 3D vortex distributions in the Berry curvature within a photonic metamaterial.}, issn = {2041-1723}, doi = {10.1038/s41467-021-22063-w}, author = {Yang, Biao and Bi, Yangang and Zhang, Rui-Xing and Zhang, Ruo-Yang and You, Oubo and Zhu, Zhihong and Feng, Jing and Sun, Hongbo and Chan, C. T. and Liu, Chao-Xing and Zhang, Shuang} } @article {orek_no_2021, title = {{NO}+ + {H}-2: {Potential} energy surface and bound state calculations}, journal = {Chem. Phys. Lett.}, volume = {771}, year = {2021}, note = {Place: RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS Publisher: ELSEVIER Type: Article}, abstract = {The first four-dimensional (4D) adiabatic potential energy surface (PES) for the interaction of NO+ cation with the H-2 molecule has been accurately determined using the CCSD(T)-F12a method with cc-pVTZ-F12 basis set augmented with mid-bond functions. A detailed characterization of the PES and lowest bound states of the H-2-NO+ complex have been provided. The H-2-NO+ PES exhibits a single global minimum with a well depth of 824.63 cm(-1) corresponding to off-planar structure with the H-2 molecule in a perpendicular orientation to the NO+ cation. The solution of the nuclear Schrodinger equation for the bound states gives a zero-point energy corrected dissociation energy of D-0 = 498.15 cm(-1) for para-H-2-NO+ complex, and of 541.35 cm(-1) for ortho-H-2-NO+.

}, keywords = {Bound states calculations, Potential energy surface}, issn = {0009-2614}, doi = {10.1016/j.cplett.2021.138511}, author = {Orek, Cahit and Uminski, Marcin and Klos, Jacek and Lique, Francois and Zuchowski, Piotr S. and Bulut, Niyazi} } @article { WOS:000662088000025, title = {Observation of a prethermal discrete time crystal}, journal = {Science}, volume = {372}, number = {6547}, year = {2021}, month = {JUN 11}, pages = {1192+}, publisher = {AMER ASSOC ADVANCEMENT SCIENCE}, type = {Article}, abstract = {Extending the framework of statistical physics to the nonequilibrium setting has led to the discovery of previously unidentified phases of matter, often catalyzed by periodic driving. However, preventing the runaway heating that is associated with driving a strongly interacting quantum system remains a challenge in the investigation of these newly discovered phases. In this work, we utilize a trapped-ion quantum simulator to observe the signatures of a nonequilibrium driven phase without disorder-the prethermal discrete time crystal. Here, the heating problem is circumvented not by disorder-induced many-body localization, but rather by high-frequency driving, which leads to an expansive time window where nonequilibrium phases can emerge. Floquet prethermalization is thus presented as a general strategy for creating, stabilizing, and studying intrinsically out-of-equilibrium phases of matter.}, issn = {0036-8075}, doi = {10.1126/science.abg8102}, author = {Kyprianidis, A. and Machado, F. and Morong, W. and Becker, P. and Collins, K. S. and Else, V, D. and Feng, L. and Hess, P. W. and Nayak, C. and Pagano, G. and Yao, N. Y. and Monroe, C.} } @article {21526, title = {Observation of {Stark} many-body localization without disorder}, journal = {Nature}, volume = {599}, year = {2021}, pages = {393{\textendash}398}, abstract = {Thermalization is a ubiquitous process of statistical physics, in which a physical system reaches an equilibrium state that is defined by a few global properties such as temperature. Even in isolated quantum many-body systems, limited to reversible dynamics, thermalization typically prevails1. However, in these systems, there is another possibility: many-body localization (MBL) can result in preservation of a non-thermal state2,3. While disorder has long been considered an essential ingredient for this phenomenon, recent theoretical work has suggested that a quantum many-body system with a spatially increasing field{\textemdash}but no disorder{\textemdash}can also exhibit MBL4, resulting in {\textquoteleft}Stark MBL{\textquoteright}5. Here we realize Stark MBL in a trapped-ion quantum simulator and demonstrate its key properties: halting of thermalization and slow propagation of correlations. Tailoring the interactions between ionic spins in an effective field gradient, we directly observe their microscopic equilibration for a variety of initial states, and we apply single-site control to measure correlations between separate regions of the spin chain. Furthermore, by engineering a varying gradient, we create a disorder-free system with coexisting long-lived thermalized and non-thermal regions. The results demonstrate the unexpected generality of MBL, with implications about the fundamental requirements for thermalization and with potential uses in engineering long-lived non-equilibrium quantum matter.

}, issn = {1476-4687}, doi = {10.1038/s41586-021-03988-0}, url = {https://doi.org/10.1038/s41586-021-03988-0}, author = {Morong, W. and Liu, F. and Becker, P. and Collins, K. S. and Feng, L. and Kyprianidis, A. and Pagano, G. and You, T. and Gorshkov, A. V. and Monroe, C.} } @article { WOS:000646067200012, title = {Optimal measurement of field properties with quantum sensor networks}, journal = {Phys. Rev. A}, volume = {103}, number = {3}, year = {2021}, month = {MAR 29}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We consider a quantum sensor network of qubit sensors coupled to a field f (x; theta) analytically parameterized by the vector of parameters theta. The qubit sensors are fixed at positions x(1), ..., x(d). While the functional form of f (x; theta) is known, the parameters theta are not. We derive saturable bounds on the precision of measuring an arbitrary analytic function q(theta) of these parameters and construct the optimal protocols that achieve these bounds. Our results are obtained from a combination of techniques from quantum information theory and duality theorems for linear programming. They can be applied to many problems, including optimal placement of quantum sensors, field interpolation, and the measurement of functionals of parametrized fields.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.103.L030601}, author = {Qian, Timothy and Bringewatt, Jacob and Boettcher, Igor and Bienias, Przemyslaw and Gorshkov, V, Alexey} } @article {brady_optimal_2021, title = {Optimal {Protocols} in {Quantum} {Annealing} and {Quantum} {Approximate} {Optimization} {Algorithm} {Problems}}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {7}, year = {2021}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {feb}, abstract = {Quantum annealing (QA) and the quantum approximate optimization algorithm (QAOA) are two special cases of the following control problem: apply a combination of two Hamiltonians to minimize the energy of a quantum state. Which is more effective has remained unclear. Here we analytically apply the framework of optimal control theory to show that generically, given a fixed amount of time, the optimal procedure has the pulsed (or {\textquotedblleft}bang-bang{\textquotedblright}) structure of QAOA at the beginning and end but can have a smooth annealing structure in between. This is in contrast to previous works which have suggested that bang-bang (i.e., QAOA) protocols are ideal. To support this theoretical work, we carry out simulations of various transverse field Ising models, demonstrating that bang-anneal-bang protocols are more common. The general features identified here provide guideposts for the nascent experimental implementations of quantum optimization algorithms.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.070505}, author = {Brady, Lucas T. and Baldwin, Christopher L. and Bapat, Aniruddha and Kharkov, Yaroslav and Gorshkov, Alexey V} } @article { WOS:000729420900001, title = {Optimizing Stabilizer Parities for Improved Logical Qubit Memories}, journal = {Phys. Rev. Lett.}, volume = {127}, number = {24}, year = {2021}, month = {DEC 6}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study variants of Shor{\textquoteright}s code that are adept at handling single-axis correlated idling errors, which are commonly observed in many quantum systems. By using the repetition code structure of the Shor{\textquoteright}s code basis states, we calculate the logical channel applied to the encoded information when subjected to coherent and correlated single qubit idling errors, followed by stabilizer measurement. Changing the signs of the stabilizer generators allows us to change how the coherent errors interfere, leading to a quantum error correcting code which performs as well as a classical repetition code of equivalent distance against these errors. We demonstrate a factor of 3.78 +/- 1.20 improvement of the logical T2{*} in a distance-3 logical qubit implemented on a trapped-ion quantum computer. Even-distance versions of our Shor-code variants are decoherence-free subspaces and fully robust to identical and independent coherent idling noise.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.127.240501}, author = {Debroy, Dripto M. and Egan, Laird and Noel, Crystal and Risinger, Andrew and Zhu, Daiwei and Biswas, Debopriyo and Cetina, Marko and Monroe, Chris and Brown, Kenneth R.} } @article { WOS:000655905200001, title = {Presence versus absence of two-dimensional Fermi surface anomalies}, journal = {Phys. Rev. B}, volume = {103}, number = {20}, year = {2021}, month = {MAY 28}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We theoretically consider Fermi surface anomalies manifesting in the temperature-dependent quasiparticle properties of two-dimensional (2D) interacting electron systems, comparing and contrasting with the corresponding three-dimensional (3D) Fermi liquid situation. In particular, employing microscopic many-body perturbative techniques, we obtain analytically the leading-order and the next-to-leading-order interaction corrections to the renormalized effective mass for three distinct physical interaction models: electron-phonon, electron-paramagnon, and electron-electron Coulomb coupling. We find that the 2D renormalized effective mass does not develop any Fermi surface anomaly due to electron-phonon interaction, manifesting O(T-2) temperature correction and thus remaining consistent with the Sommerfeld expansion of the noninteracting Fermi function, in contrast to the corresponding 3D situation where the temperature correction to the renormalized effective mass has the anomalous T-2 log T behavior. In contrast, both electron-paramagnon and electron-electron interactions lead to the anomalous O(T) corrections to the 2D effective mass renormalization in contrast to T-2 log T behavior in the corresponding 3D interacting systems. We provide detailed analytical results, and comment on the conditions under which a T-2 log T term could possibly arise in the 2D quasiparticle effective mass from electron-phonon interactions. We also compare results for the temperature-dependent specific heat in the interacting 2D and 3D Fermi systems, using the close connection between the effective mass and specific heat.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.103.205154}, author = {Buterakos, Donovan and DinhDuy Vu and Yu, Jiabin and Das Sarma, Sankar} } @article { WOS:000669569500009, title = {Protocols for estimating multiple functions with quantum sensor networks: Geometry and performance}, journal = {Phys. Rev. Res.}, volume = {3}, number = {3}, year = {2021}, month = {JUL 2}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We consider the problem of estimating multiple analytic functions of a set of local parameters via qubit sensors in a quantum sensor network. To address this problem, we highlight a generalization of the sensor symmetric performance bounds of Rubio et al., {[}J. Phys. A 53, 344001 (2020)] and develop an optimized sequential protocol for measuring such functions. We compare the performance of both approaches to one another and to local protocols that do not utilize quantum entanglement, emphasizing the geometric significance of the coefficient vectors of the measured functions in determining the best choice of measurement protocol. We show that, in many cases, especially for a large number of sensors, the optimized sequential protocol results in more accurate measurements than the other strategies. In addition, in contrast to the sensor symmetric approach, the sequential protocol is known to always be explicitly implementable. The sequential protocol is very general and has a wide range of metrological applications.}, doi = {10.1103/PhysRevResearch.3.033011}, author = {Bringewatt, Jacob and Boettcher, Igor and Niroula, Pradeep and Bienias, Przemyslaw and Gorshkov, V, Alexey} } @article { WOS:000662078500026, title = {Purcell-Enhanced Single Photon Source Based on a Deterministically Placed WSe2 Monolayer Quantum Dot in a Circular Bragg Grating Cavity}, journal = {Nano Lett.}, volume = {21}, number = {11}, year = {2021}, month = {JUN 9}, pages = {4715-4720}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {We demonstrate a deterministic Purcell-enhanced single photon source realized by integrating an atomically thin WSe2 layer with a circular Bragg grating cavity. The cavity significantly enhances the photoluminescence from the atomically thin layer and supports single photon generation with g((2)) (0) < 0.25. We observe a consistent increase of the spontaneous emission rate for WSe2 emitters located in the center of the Bragg grating cavity. These WSe2 emitters are self-aligned and deterministically coupled to such a broadband cavity, configuring a new generation of deterministic single photon sources, characterized by their simple and low-cost production and intrinsic scalability.}, keywords = {bullseyes cavities, Purcell effect, Quantum Dots, single photons, two-dimensional materials}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.1c00978}, author = {Iff, Oliver and Buchinger, Quirin and Moczala-Dusanowska, Magdalena and Kamp, Martin and Betzold, Simon and Davanco, Marcelo and Srinivasan, Kartik and Tongay, Sefaattin and Anton-Solanas, Carlos and Hoefling, Sven and Schneider, Christian} } @article { WOS:000726704700012, title = {Quantum circuits for the realization of equivalent forms of one-dimensional discrete-time quantum walks on near-term quantum hardware}, journal = {Phys. Rev. A}, volume = {104}, number = {6}, year = {2021}, month = {DEC 1}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Quantum walks are a promising framework for developing quantum algorithms and quantum simulations. They represent an important test case for the application of quantum computers. Here we present different forms of discrete-time quantum walks (DTQWs) and show their equivalence for physical realizations. Using an appropriate digital mapping of the position space on which a walker evolves to the multiqubit states of a quantum processor, we present different configurations of quantum circuits for the implementation of DTQWs in one-dimensional position space. We provide example circuits for a five-qubit processor and address scalability to higher dimensions as well as larger quantum processors.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.104.062401}, author = {Singh, Shivani and Alderete, C. Huerta and Balu, Radhakrishnan and Monroe, Christopher and Linke, Norbert M. and Chandrashekar, C. M.} } @article { WOS:000674685900001, title = {Quantum Computer Systems for Scientific Discovery}, journal = {PRX Quantum}, volume = {2}, number = {1}, year = {2021}, month = {FEB 24}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The great promise of quantum computers comes with the dual challenges of building them and finding their useful applications. We argue that these two challenges should be considered together, by codesigning full-stack quantum computer systems along with their applications in order to hasten their development and potential for scientific discovery. In this context, we identify scientific and community needs, opportunities, a sampling of a few use case studies, and significant challenges for the development of quantum computers for science over the next 2-10 years. This document is written by a community of university, national laboratory, and industrial researchers in the field of Quantum Information Science and Technology, and is based on a summary from a U.S. National Science Foundation workshop on Quantum Computing held on October 21-22, 2019 in Alexandria, VA.}, doi = {10.1103/PRXQuantum.2.017001}, author = {Alexeev, Yuri and Bacon, Dave and Brown, Kenneth R. and Calderbank, Robert and Carr, Lincoln D. and Chong, Frederic T. and DeMarco, Brian and Englund, Dirk and Farhi, Edward and Fefferman, Bill and Gorshkov, V, Alexey and Houck, Andrew and Kim, Jungsang and Kimmel, Shelby and Lange, Michael and Lloyd, Seth and Lukin, Mikhail D. and Maslov, Dmitri and Maunz, Peter and Monroe, Christopher and Preskill, John and Roetteler, Martin and Savage, Martin J. and Thompson, Jeff} } @article { WOS:000691579200002, title = {Quantum routing with fast reversals}, journal = {Quantum}, volume = {5}, year = {2021}, month = {AUG 31}, publisher = {VEREIN FORDERUNG OPEN ACCESS PUBLIZIERENS QUANTENWISSENSCHAF}, type = {Article}, abstract = {We present methods for implementing arbitrary permutations of qubits under interaction constraints. Our protocols make use of previous methods for rapidly reversing the order of qubits along a path. Given nearest-neighbor interactions on a path of length n, we show that there exists a constant epsilon approximate to 0.034 such that the quantum routing time is at most (1 - epsilon)n, whereas any SWAP-based protocol needs at least time n - 1. This represents the first known quantum advantage over SWAP-based routing methods and also gives improved quantum routing times for realistic architectures such as grids. Furthermore, we show that our algorithm approaches a quantum routing time of 2n/3 in expectation for uniformly random permutations, whereas SWAP-based protocols require time n asymptotically. Additionally, we consider sparse permutations that route k <= n qubits and give algorithms with quantum routing time at most n/3 + O(k(2)) on paths and at most 2r/3 + O(k(2)) on general graphs with radius r.}, issn = {2521-327X}, author = {Bapat, Aniruddha and Childs, Andrew M. and V. Gorshkov, Alexey and King, Samuel and Schoute, Eddie and Shastri, Hrishee} } @article { WOS:000674685900003, title = {Quantum Simulators: Architectures and Opportunities}, journal = {PRX Quantum}, volume = {2}, number = {1}, year = {2021}, month = {FEB 24}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Quantum simulators are a promising technology on the spectrum of quantum devices from specialized quantum experiments to universal quantum computers. These quantum devices utilize entanglement and many-particle behavior to explore and solve hard scientific, engineering, and computational problems. Rapid development over the last two decades has produced more than 300 quantum simulators in operation worldwide using a wide variety of experimental platforms. Recent advances in several physical architectures promise a golden age of quantum simulators ranging from highly optimized special purpose simulators to flexible programmable devices. These developments have enabled a convergence of ideas drawn from fundamental physics, computer science, and device engineering. They have strong potential to address problems of societal importance, ranging from understanding vital chemical processes, to enabling the design of new materials with enhanced performance, to solving complex computational problems. It is the position of the community, as represented by participants of the National Science Foundation workshop on {\textquoteleft}{\textquoteleft}Programmable Quantum Simulators,{{\textquoteright}{\textquoteright}} that investment in a national quantum simulator program is a high priority in order to accelerate the progress in this field and to result in the first practical applications of quantum machines. Such a program should address two areas of emphasis: (1) support for creating quantum simulator prototypes usable by the broader scientific community, complementary to the present universal quantum computer effort in industry; and (2) support for fundamental research carried out by a blend of multi-investigator, multidisciplinary collaborations with resources for quantum simulator software, hardware, and education. This document is a summary from a U.S. National Science Foundation supported workshop held on 16-17 September 2019 in Alexandria, VA. Attendees were charged to identify the scientific and community needs, opportunities, and significant challenges for quantum simulators over the next 2-5 years.}, doi = {10.1103/PRXQuantum.2.017003}, author = {Altman, Ehud and Brown, Kenneth R. and Carleo, Giuseppe and Carr, Lincoln D. and Demler, Eugene and Chin, Cheng and DeMarco, Brian and Economou, Sophia E. and Eriksson, Mark A. and Fu, Kai-Mei C. and Greiner, Markus and Hazzard, Kaden R. A. and Hulet, Randall G. and Kollar, Alicia J. and Lev, Benjamin L. and Lukin, Mikhail D. and Ma, Ruichao and Mi, Xiao and Misra, Shashank and Monroe, Christopher and Murch, Kater and Nazario, Zaira and Ni, Kang-Kuen and Potter, Andrew C. and Roushan, Pedram and Saffman, Mark and Schleier-Smith, Monika and Siddiqi, Irfan and Simmonds, Raymond and Singh, Meenakshi and Spielman, I. B. and Temme, Kristan and Weiss, David S. and Vuckovic, Jelena and Vuletic, Vladan and Ye, Jun and Zwierlein, Martin} } @article { WOS:000655928700001, title = {Quench Dynamics of a Fermi Gas with Strong Nonlocal Interactions}, journal = {Phys. Rev. X}, volume = {11}, number = {2}, year = {2021}, month = {MAY 17}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We induce strong nonlocal interactions in a 2D Fermi gas in an optical lattice using Rydberg dressing. The system is approximately described by a t - V model on a square lattice where the fermions experience isotropic nearest-neighbor interactions and are free to hop only along one direction. We measure the interactions using many-body Ramsey interferometry and study the lifetime of the gas in the presence of tunneling, finding that tunneling does not reduce the lifetime. To probe the interplay of nonlocal interactions with tunneling, we investigate the short-time-relaxation dynamics of charge-density waves in the gas. We find that strong nearest-neighbor interactions slow down the relaxation. Our work opens the door for quantum simulations of systems with strong nonlocal interactions such as extended Fermi-Hubbard models.}, issn = {2160-3308}, doi = {10.1103/PhysRevX.11.021036}, author = {Guardado-Sanchez, Elmer and Spar, Benjamin M. and Schauss, Peter and Belyansky, Ron and Young, Jeremy T. and Bienias, Przemyslaw and Gorshkov, V, Alexey and Iadecola, Thomas and Bakr, Waseem S.} } @article { WOS:000704295900053, title = {Single-Molecule Measurements Spatially Probe States Involved in Electron Transfer from CdSe/CdS Core/Shell Nanorods}, journal = {J. Phys. Chem. C}, volume = {125}, number = {38, SI}, year = {2021}, month = {SEP 30}, pages = {21246-21253}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {Semiconductor nanorods with charge-accepting molecules adsorbed on their surfaces serve as model systems for solar energy conversion. An electron photoexcited from the valence band of the nanorod to a high-energy state in the conduction band will relax and transfer to a state in the molecule, producing a long-lived charge-separated state that facilitates charge extraction and thereby enables photochemical reactions. Characterizing the dynamics of the charge-separation process and the electronic states involved is essential for a microscopic understanding of photocatalysis involving these materials, but this information is obscured in ensemble measurements due to the random placement of molecules on the nanorod surfaces. Here, we show that measurements on individual CdSe/CdS core/shell nanorods functionalized by single methyl viologen molecules provide information about the distribution of electron-transfer rates from confined states in the nanorods to states in the molecules. By comparing this transfer-rate distribution to the predictions of a tight-binding model, we find that charge transfer most likely involves hot electrons in an excited conduction-band state, rather than electrons that have fully thermalized to the conduction-band edge. The ability to extract hot electrons from semiconductor nanocrystals may help enable energy-efficient photocatalysis, and the single-particle charge-transfer method may serve as a widely applicable tool to probe the spatial distribution of electronic states in nanocrystals.}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.1c06581}, author = {Morin, Rachel M. and Bryant, Garnett W. and Shevchenko, V, Elena and Sha, Yuchen and Pelton, Matthew} } @article { WOS:000707419200012, title = {Singularities in nearly uniform one-dimensional condensates due to quantum diffusion}, journal = {Phys. Rev. A}, volume = {104}, number = {4}, year = {2021}, month = {OCT 14}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Dissipative systems often exhibit wavelength-dependent loss rates. One prominent example is Rydberg polaritons formed by electromagnetically induced transparency, which have long been a leading candidate for studying the physics of interacting photons and also hold promise as a platform for quantum information. In this system, dissipation is in the form of quantum diffusion, i.e., proportional to k(2) (k being the wavevector) and vanishing at long wavelengths as k -> 0. Here, we show that one-dimensional condensates subject to this type of loss are unstable to long-wavelength density fluctuations in an unusual manner: after a prolonged period in which the condensate appears to relax to a uniform state, local depleted regions quickly form and spread ballistically throughout the system. We connect this behavior to the leading-order equation for the nearly uniform condensate-a dispersive analog to the Kardar-Parisi-Zhang equation-which develops singularities in finite time. Furthermore, we show that the wavefronts of the depleted regions are described by purely dissipative solitons within a pair of hydrodynamic equations, with no counterpart in lossless condensates. We close by discussing conditions under which such singularities and the resulting solitons can be physically realized.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.104.L041303}, author = {Baldwin, C. L. and Bienias, P. and Gorshkov, V, A. and Gullans, M. J. and Maghrebi, M.} } @article { WOS:000672657300001, title = {Solitons in lattice field theories via tight-binding supersymmetry}, journal = {J. High Energy Phys.}, number = {7}, year = {2021}, month = {JUL 9}, publisher = {SPRINGER}, type = {Article}, abstract = {Reflectionless potentials play an important role in constructing exact solutions to classical dynamical systems (such as the Korteweg-de Vries equation), non-perturbative solutions of various large-N field theories (such as the Gross-Neveu model), and closely related solitonic solutions to the Bogoliubov-de Gennes equations in the theory of superconductivity. These solutions rely on the inverse scattering method, which reduces these seemingly unrelated problems to identifying reflectionless potentials of an auxiliary one-dimensional quantum scattering problem. There are several ways of constructing these potentials, one of which is quantum mechanical supersymmetry (SUSY). In this paper, motivated by recent experimental platforms, we generalize this framework to develop a theory of lattice solitons. We first briefly review the classical inverse scattering method in the continuum limit, focusing on the Korteweg-de Vries (KdV) equation and SU(N) Gross-Neveu model in the large N limit. We then generalize this methodology to lattice versions of interacting field theories. Our analysis hinges on the use of trace identities, which are relations connecting the potential of an equation of motion to the scattering data. For a discrete Schrodinger operator, such trace identities had been known as far back as Toda; however, we derive a new set of identities for the discrete Dirac operator. We then use these identities in a lattice Gross-Neveu and chiral Gross-Neveu (Nambu-Jona-Lasinio) model to show that lattice solitons correspond to reflectionless potentials associated with the discrete scattering problem. These models are of significance as they are equivalent to a mean-field theory of a lattice superconductor. To explicitly construct these solitons, we generalize supersymmetric quantum mechanics to tight-binding models. We show that a matrix transformation exists that maps a tight-binding model to an isospectral one which shares the same structure and scattering properties. The corresponding soliton solutions have both modulated hopping and onsite potential, the former of which has no analogue in the continuum limit. We explicitly compute both topological and non-topological soliton solutions as well as bound state spectra in the aforementioned models.}, keywords = {Lattice Integrable Models, Lattice Quantum Field Theory, Solitons Monopoles and Instantons}, issn = {1029-8479}, doi = {10.1007/JHEP07(2021)055}, author = {Balasubramanian, Shankar and Patoary, Abu and Galitski, Victor} } @article { WOS:000736648600001, title = {Spin-Valley Qubit Dynamics in Exchange-Coupled Silicon Quantum Dots}, journal = {PRX Quantum}, volume = {2}, number = {4}, year = {2021}, month = {DEC 23}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The presence of valley states is a significant obstacle to realizing quantum information technologies in silicon quantum dots, as leakage into alternate valley states can introduce errors into the computation. We use a perturbative analytical approach to study the dynamics of exchange-coupled quantum dots with valley degrees of freedom. We show that if the valley splitting is large and electrons are not properly initialized to valley eigenstates, then the time evolution of the system will lead to spin-valley entanglement. Spin-valley entanglement will also occur if the valley splitting is small and electrons are not initialized to the same valley state. Additionally, we show that for small valley splitting, spin-valley entanglement does not affect the measurement probabilities of two-qubit systems; however, systems with more qubits will be affected. This means that two-qubit gate fidelities measured in two-qubit systems may miss the effects of valley degrees of freedom. Our work shows how the existence of valleys may adversely affect multiqubit fidelities even when the system temperature is very low. Although this is not an immediate problem in Si qubits, because the current focus is on controlling individual qubits, our work points to a possible future issue in many-qubit Si circuits.}, doi = {10.1103/PRXQuantum.2.040358}, author = {Buterakos, Donovan and Das Sarma, Sankar} } @article {shivam_studying_2021, title = {Studying {Viral} {Populations} with {Tools} from {Quantum} {Spin} {Chains}}, journal = {J. Stat. Phys.}, volume = {182}, number = {2}, year = {2021}, note = {Place: ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES Publisher: SPRINGER Type: Article}, month = {feb}, abstract = {We study Eigen{\textquoteright}s model of quasi-species (Eigen in Selforganization of matter and the evolution of biological macromolecules. Naturwissenschaften 58(10):465, 1971), characterized by sequences that replicate with a specified fitness and mutate independently at single sites. The evolution of the population vector in time is then closely related to that of quantum spins in imaginary time. We employ multiple perspectives and tools from interacting quantum systems to examine growth and collapse of realistic viral populations, specifically considering excessive mutations in certain HIV proteins. All approaches used, including the simplest perturbation theory, give consistent results.

}, keywords = {Biological evolution, HIV, Quantum spin chains}, issn = {0022-4715}, doi = {10.1007/s10955-021-02716-2}, author = {Shivam, Saumya and Baldwin, Christopher L. and Barton, John and Kardar, Mehran and Sondhi, S. L.} } @article { WOS:000655930100005, title = {Topological Defect Engineering and PT Symmetry in Non-Hermitian Electrical Circuits}, journal = {Phys. Rev. Lett.}, volume = {126}, number = {21}, year = {2021}, month = {MAY 28}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We employ electric circuit networks to study topological states of matter in non-Hermitian systems enriched by parity-time symmetry PT and chiral symmetry anti-PT (APT). The topological structure manifests itself in the complex admittance bands which yields excellent measurability and signal to noise ratio. We analyze the impact of PT-symmetric gain and loss on localized edge and defect states in a non-Hermitian Su-Schrieffer-Heeger (SSH) circuit. We realize all three symmetry phases of the system, including the APT-symmetric regime that occurs at large gain and loss. We measure the admittance spectrum and eigenstates for arbitrary boundary conditions, which allows us to resolve not only topological edge states, but also a novel PT-symmetric Z(2) invariant of the bulk. We discover the distinct properties of topological edge states and defect states in the phase diagram. In the regime that is not PT symmetric, the topological defect state disappears and only reemerges when APT symmetry is reached, while the topological edge states always prevail and only experience a shift in eigenvalue. Our findings unveil a future route for topological defect engineering and tuning in non-Hermitian systems of arbitrary dimension.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.126.215302}, author = {Stegmaier, Alexander and Imhof, Stefan and Helbig, Tobias and Hoefmann, Tobias and Lee, Ching Hua and Kremer, Mark and Fritzsche, Alexander and Feichtner, Thorsten and Klembt, Sebastian and Hofling, Sven and Boettcher, Igor and Fulga, Ion Cosma and Ma, Libo and Schmidt, Oliver G. and Greiter, Martin and Kiessling, Tobias and Szameit, Alexander and Thomale, Ronny} } @article {21626, title = {Topological Order and Criticality in (2+1)D Monitored Random Quantum Circuits}, journal = {Phys. Rev. Lett.}, volume = {127}, year = {2021}, month = {Dec}, pages = {235701}, doi = {10.1103/PhysRevLett.127.235701}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.127.235701}, author = {Lavasani, Ali and Alavirad, Yahya and Barkeshli, Maissam} } @article { WOS:000655094800001, title = {Towards integrated photonic interposers for processing octave-spanning microresonator frequency combs}, journal = {Light-Sci. Appl.}, volume = {10}, number = {1}, year = {2021}, month = {MAY 26}, publisher = {SPRINGERNATURE}, type = {Article}, abstract = {Microcombs-optical frequency combs generated in microresonators-have advanced tremendously in the past decade, and are advantageous for applications in frequency metrology, navigation, spectroscopy, telecommunications, and microwave photonics. Crucially, microcombs promise fully integrated miniaturized optical systems with unprecedented reductions in cost, size, weight, and power. However, the use of bulk free-space and fiber-optic components to process microcombs has restricted form factors to the table-top. Taking microcomb-based optical frequency synthesis around 1550 nm as our target application, here, we address this challenge by proposing an integrated photonics interposer architecture to replace discrete components by collecting, routing, and interfacing octave-wide microcomb-based optical signals between photonic chiplets and heterogeneously integrated devices. Experimentally, we confirm the requisite performance of the individual passive elements of the proposed interposer-octave-wide dichroics, multimode interferometers, and tunable ring filters, and implement the octave-spanning spectral filtering of a microcomb, central to the interposer, using silicon nitride photonics. Moreover, we show that the thick silicon nitride needed for bright dissipative Kerr soliton generation can be integrated with the comparatively thin silicon nitride interposer layer through octave-bandwidth adiabatic evanescent coupling, indicating a path towards future system-level consolidation. Finally, we numerically confirm the feasibility of operating the proposed interposer synthesizer as a fully assembled system. Our interposer architecture addresses the immediate need for on-chip microcomb processing to successfully miniaturize microcomb systems and can be readily adapted to other metrology-grade applications based on optical atomic clocks and high-precision navigation and spectroscopy.}, issn = {2047-7538}, doi = {10.1038/s41377-021-00549-y}, author = {Rao, Ashutosh and Moille, Gregory and Lu, Xiyuan and Westly, Daron A. and Sacchetto, Davide and Geiselmann, Michael and Zervas, Michael and Papp, Scott B. and Bowers, John and Srinivasan, Kartik} } @article {19291, title = {Tunable Three-Body Loss in a Nonlinear Rydberg Medium}, journal = {Phys. Rev. Lett.}, volume = {126}, year = {2021}, month = {Apr}, pages = {173401}, abstract = {Long-range Rydberg interactions, in combination with electromagnetically induced transparency (EIT), give rise to strongly interacting photons where the strength, sign, and form of the interactions are widely tunable and controllable. Such control can be applied to both coherent and dissipative interactions, which provides the potential for generating novel few-photon states. Recently it has been shown that Rydberg-EIT is a rare system in which three-body interactions can be as strong or stronger than two-body interactions. In this work, we study three-body scattering loss for Rydberg-EIT in a wide regime of single and two-photon detunings. Our numerical simulations of the full three-body wave function and analytical estimates based on Fermi{\textquoteright}s golden rule strongly suggest that the observed features in the outgoing photonic correlations are caused by the resonant enhancement of the three-body losses.

}, doi = {10.1103/PhysRevLett.126.173401}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.126.173401}, author = {Ornelas-Huerta, D. P. and Bienias, Przemyslaw and Craddock, Alexander N. and Gullans, Michael J. and Hachtel, Andrew J. and Kalinowski, Marcin and Lyon, Mary E. and Gorshkov, Alexey V. and Rolston, S. L. and Porto, J. V.} } @article { WOS:000654369300061, title = {Two-beam coupling in the production of quantum correlated images by four-wave mixing}, journal = {Opt. Express}, volume = {29}, number = {11}, year = {2021}, month = {MAY 24}, pages = {16665-16675}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {We investigate the effect of 2-beam coupling in different imaging geometries in generating intensity-difference squeezing from four-wave mixing (4WM) in Rb atomic vapors. A recently-introduced dual-seeding technique can cancel out the classical noise in a seeded four-wave mixing process. This dual-seeding technique, however, can introduce new complications that involve 2-beam coupling between different seeded spatial modes in the atomic vapor and can ruin squeezing at frequencies on the order of the atomic linewidth and below. This complicates some forms of quantum imaging using these systems. Here we show that seeding the 4WM process with skew rays can eliminate the excess noise caused by 2-beam coupling. To avoid 2-beam coupling in bright, seeded images, it is important to re-image the object in the gain medium, instead of focussing through it. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {1094-4087}, doi = {10.1364/OE.424392}, author = {Wu, Meng-Chang and Brewer, Nicholas R. and Speirs, Rory W. and Jones, Kevin M. and Lett, Paul D.} } @article { WOS:000707473300010, title = {Yang-Lee edge singularity triggered entanglement transition}, journal = {Phys. Rev. B}, volume = {104}, number = {16}, year = {2021}, month = {OCT 11}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We show that a class of PT symmetric non-Hermitian Hamiltonians realizing the Yang-Lee edge singularity exhibits an entanglement transition in the long-time steady state evolved under the Hamiltonian. Such a transition is induced by a level crossing triggered by the critical point associated with the Yang-Lee singularity and hence is first order in nature. At the transition, the entanglement entropy of the steady state jumps discontinuously from a volume-law to an area-law scaling. We exemplify this mechanism using a one-dimensional transverse field Ising model with additional imaginary fields, as well as the spin-1 Blume-Capel model and the three-state Potts model. We further make a connection to the forced-measurement induced entanglement transition in a Floquet nonunitary circuit subject to continuous measurements followed by post-selections. Our results demonstrate a new mechanism for entanglement transitions in non-Hermitian systems harboring a critical point.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.104.L161107}, author = {Jian, Shao-Kai and Yang, Zhi-Cheng and Bi, Zhen and Chen, Xiao} } @article {bulmash_absolute_2020, title = {Absolute anomalies in (2+1){D} symmetry-enriched topological states and exact (3+1){D} constructions}, journal = {Phys. Rev. Res.}, volume = {2}, number = {4}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {oct}, abstract = {Certain patterns of symmetry fractionalization in (2+1)-dimensional [(2+1)D] topologically ordered phases of matter can be anomalous, which means that they possess an obstruction to being realized in purely (2+1)D. In this paper we demonstrate how to compute the anomaly for symmetry-enriched topological states of bosons in complete generality. We demonstrate how, given any unitary modular tensor category (UMTC) and symmetry fractionalization class for a global symmetry group G, one can define a (3+1)-dimensional [(3+1)D] topologically invariant path integral in terms of a state sum for a G-symmetry-protected topological (SPT) state. We present an exactly solvable Hamiltonian for the system and demonstrate explicitly a (2+1)D G-symmetric surface termination that hosts deconfined anyon excitations described by the given UMTC and symmetry fractionalization class. We present concrete algorithms that can be used to compute anomaly indicators in general. Our approach applies to general symmetry groups, including anyon-permuting and antiunitary symmetries. In addition to providing a general way to compute the anomaly, our result also shows, by explicit construction, that every symmetry fractionalization class for any UMTC can be realized at the surface of a (3+1)D SPT state. As a by-product, this construction also provides a way of explicitly seeing how the algebraic data that defines symmetry fractionalization in general arises in the context of exactly solvable models. In the case of unitary orientation-preserving symmetries, our results can also be viewed as providing a method to compute the H-4(G, U(1)) obstruction that arises in the theory of G-crossed braided tensor categories, for which no general method has been presented to date.}, doi = {10.1103/PhysRevResearch.2.043033}, author = {Bulmash, Daniel and Barkeshli, Maissam} } @article { ISI:000528518000008, title = {Accurate Prediction of Clock Transitions in a Highly Charged Ion with Complex Electronic Structure}, journal = {Phys. Rev. Lett.}, volume = {124}, number = {16}, year = {2020}, month = {APR 24}, pages = {163001}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We develop a broadly applicable approach that drastically increases the ability to predict the properties of complex atoms accurately. We apply it to the case of Ir-17(+), which is of particular interest for the development of novel atomic clocks with a high sensitivity to the variation of the fine-structure constant and to dark matter searches. In general, clock transitions are weak and very difficult to identify without accurate theoretical predictions. In the case of Ir-17(+), even stronger electric-dipole (El) transitions have eluded observation despite years of effort, raising the possibility that the theoretical predictions are grossly wrong. In this work, we provide accurate predictions of the transition wavelengths and E1 transition rates for Ir-17(+). Our results explain the lack of observations of the E1 transitions and provide a pathway toward the detection of clock transitions. The computational advances we demonstrate in this work are widely applicable to most elements in the periodic table and will allow us to solve numerous problems in atomic physics, astrophysics, and plasma physics.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.124.163001}, author = {Cheung, C. and Safronova, M. S. and Porsev, S. G. and Kozlov, M. G. and Tupitsyn, I. I. and Bondarev, I. A.} } @article {zhang_branching_2020, title = {Branching fractions for {P}-3/2 decays in {Ba}+}, journal = {Phys. Rev. A}, volume = {101}, number = {6}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jun}, abstract = {Branching fractions for decays from the P-3/2 level in B-138 at have been measured with a single laser-cooled ion. Decay probabilities to S-1/2, D-3/2, and D-5/2 are determined to be 0.741716(71), 0.028031(23), and 0.230253(61), respectively, which are an order-of-magnitude improvement over previous results. Our methodology only involves optical pumping and state detection, and is hence relatively free of systematic effects. Measurements are carried out in two different ways to check for consistency. Our analysis also includes a measurement of the D-5/2 lifetime, for which we obtain 30.14(40) s.}, issn = {1050-2947}, doi = {10.1103/PhysRevA.101.062515}, author = {Zhang, Zhiqiang and Arnold, K. J. and Chanu, S. R. and Kaewuam, R. and Safronova, M. S. and Barrett, M. D.} } @article { ISI:000548140000001, title = {Branching fractions for P-3/2 decays in Ba+}, journal = {Phys. Rev. A}, volume = {101}, number = {6}, year = {2020}, month = {JUN 24}, pages = {062515}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Branching fractions for decays from the P-3/2 level in B-138 at have been measured with a single laser-cooled ion. Decay probabilities to S-1/2, D-3/2, and D-5/2 are determined to be 0.741716(71), 0.028031(23), and 0.230253(61), respectively, which are an order-of-magnitude improvement over previous results. Our methodology only involves optical pumping and state detection, and is hence relatively free of systematic effects. Measurements are carried out in two different ways to check for consistency. Our analysis also includes a measurement of the D-5/2 lifetime, for which we obtain 30.14(40) s.}, issn = {1050-2947}, doi = {10.1103/PhysRevA.101.062515}, author = {Zhang, Zhiqiang and Arnold, K. J. and Chanu, S. R. and Kaewuam, R. and Safronova, M. S. and Barrett, M. D.} } @article {moille_broadband_2020, title = {Broadband resonator-waveguide coupling for efficient extraction of octave-spanning microcombs}, journal = {Opt. Lett.}, volume = {45}, number = {17}, year = {2020}, note = {Place: 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA Publisher: OPTICAL SOC AMER Type: Correction}, month = {sep}, pages = {4939}, issn = {0146-9592}, doi = {10.1364/OL.405775}, author = {Moille, Gregory and Li, Qing and Briles, Travis C. and Yu, Su-Peng and Drake, Tara and Lu, Xiyuan and Rao, Ashutosh and Westly, Daron and Papp, Scott B. and Srinivasan, Kartik} } @conference {barik_chiral_2020-1, title = {Chiral coupling of a quantum emitter in a topological photonic resonator}, booktitle = {2020 Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, address = {345 E 47TH ST, NEW YORK, NY 10017 USA}, abstract = {Here we demonstrate chiral light-matter interactions in a topological photonic crystal resonator. We achieve this by employing valley-Hall topological edge states to create a helical resonator at the interface of two topologically distinct regions. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Barik, Sabyasachi and Karasahin, Aziz and Mittal, Sunil and Hafezi, Mohammad and Waks, Edo} } @article { ISI:000531732200005, title = {Chiral quantum optics using a topological resonator}, journal = {Phys. Rev. B}, volume = {101}, number = {20}, year = {2020}, month = {MAY 12}, pages = {205303}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Chiral nanophotonic components, such as waveguides and resonators coupled to quantum emitters, provide a fundamentally new approach to manipulate light-matter interactions. The recent emergence of topological photonics has provided a new paradigm to realize helical/chiral nanophotonic structures that are flexible in design and, at the same time, robust against sharp bends and disorder. Here we demonstrate such a topologically protected chiral nanophotonic resonator that is strongly coupled to a solid-state quantum emitter. Specifically, we employ the valley-Hall effect in a photonic crystal to achieve topological edge states at an interface between two topologically distinct regions. Our helical resonator supports two counterpropagating edge modes with opposite polarizations. We first show chiral coupling between the topological resonator and the quantum emitter such that the emitter emits preferably into one of the counterpropagating edge modes depending upon its spin. Subsequently, we demonstrate strong coupling between the resonator and the quantum emitter using resonant Purcell enhancement in the emission intensity by a factor of 3.4. Such chiral resonators could enable designing complex nanophotonic circuits for quantum information processing and studying novel quantum many-body dynamics.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.101.205303}, author = {Barik, Sabyasachi and Karasahin, Aziz and Mittal, Sunil and Waks, Edo and Hafezi, Mohammad} } @article { ISI:000564912400007, title = {Coherent optical nanotweezers for ultracold atoms}, journal = {Phys. Rev. A}, volume = {102}, number = {1}, year = {2020}, month = {JUL 7}, pages = {013306}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {There has been a recent surge of interest and progress in creating subwavelength free-space optical potentials for ultracold atoms. A key open question is whether geometric potentials, which are repulsive and ubiquitous in the creation of subwavelength free-space potentials, forbid the creation of narrow traps with long lifetimes. Here, we show that it is possible to create such traps. We propose two schemes for realizing subwavelength traps and demonstrate their superiority over existing proposals. We analyze the lifetime of atoms in such traps and show that long-lived bound states are possible. This work allows for subwavelength control and manipulation of ultracold matter, with applications in quantum chemistry and quantum simulation.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.102.013306}, author = {Bienias, P. and Subhankar, S. and Wang, Y. and Tsui, T-C and Jendrzejewski, F. and Tiecke, T. and Juzeliunas, G. and Jiang, L. and Rolston, S. L. and Porto, V, J. and Gorshkov, V, A.} } @article { ISI:000505979700006, title = {Collisions of room-temperature helium with ultracold lithium and the van der Waals bound state of HeLi}, journal = {Phys. Rev. A}, volume = {101}, number = {1}, year = {2020}, month = {JAN 6}, pages = {012702}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We have computed the thermally averaged total, elastic rate coefficient for the collision of a room-temperature helium atom with an ultracold lithium atom. This rate coefficient has been computed as part of the characterization of a cold-atom vacuum sensor based on laser-cooled Li-6 or Li-7 atoms that will operate in the ultrahigh-vacuum (p < 10(-6) Pa) and extreme-high-vacuum (p < 10(-10) Pa) regimes. The analysis involves computing the X (2) Sigma(+) HeLi Born-Oppenheimer potential followed by the numerical solution of the relevant radial Schrodinger equation. The potential is computed using a single-reference-coupled-cluster electronic-structure method with basis sets of different completeness in order to characterize our uncertainty budget. We predict that the rate coefficient for a 300 K helium gas and a 1 mu K Li gas is 1.467(13) x 10(-9) cm(3)/s for He-4 + Li-6 and 1.471(13) x 10(-9) cm(3)/s for He-4 + Li-7, where the numbers in parentheses are the one-standard-deviation uncertainties in the last two significant digits. We quantify the temperature dependence as well. Finally, we evaluate the s-wave scattering length and binding of the single van der Waals bound state of HeLi. We predict that this weakly bound level has a binding energy of -0.0064(43) x hc cm(-1) and -0.0122(67) x hc cm(-1) for He-4 + Li-6 and He-4 + Li-7, respectively. The calculated binding energy of He-4 + Li-7 is consistent with the sole experimental determination.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.101.012702}, author = {Makrides, Constantinos and Barker, Daniel S. and Fedchak, James A. and Scherschligt, Julia and Eckel, Stephen and Tiesinga, Eite} } @article { ISI:000581926500001, title = {Confinement of an alkaline-earth element in a grating magneto-optical trap}, journal = {Rev. Sci. Instrum.}, volume = {91}, number = {10}, year = {2020}, month = {OCT 1}, pages = {103202}, publisher = {AMER INST PHYSICS}, type = {Article}, abstract = {We demonstrate a compact magneto-optical trap (MOT) of alkaline-earth atoms using a nanofabricated diffraction grating chip. A single input laser beam, resonant with the broad S-1(0) -> P-1(1) transition of strontium, forms the MOT in combination with three diffracted beams from the grating chip and a magnetic field produced by permanent magnets. A differential pumping tube limits the effect of the heated, effusive source on the background pressure in the trapping region. The system has a total volume of around 2.4 l. With our setup, we have trapped up to 5 x 10(6) Sr-88 atoms at a temperature of similar to 6 mK, and with a trap lifetime of similar to 1 s. Our results will aid the effort to miniaturize quantum technologies based on alkaline-earth atoms.}, issn = {0034-6748}, doi = {10.1063/5.0019551}, author = {Sitaram, A. and Elgee, P. K. and Campbell, G. K. and Klimov, N. N. and Eckel, S. and Barker, D. S.} } @article { ISI:000557736300003, title = {Detection of the Lowest-Lying Odd-Parity Atomic Levels in Actinium}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {7}, year = {2020}, month = {AUG 10}, pages = {073001}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Two lowest-energy odd-parity atomic levels of actinium, 7s(2)7p(2)P(1/2)(0), 7s(2)7p(2)P(3/)(2)(0), were observed via two-step resonant laser-ionization spectroscopy and their respective energies were measured to be 7477.36(4) and 12 276.59(2) cm(-1). The lifetimes of these states were determined as 668(11) and 255(7) ns, respectively. In addition, we observed the effect of the hyperfine structure on the line for the transition to P-2(3)/2(0). These properties were calculated using a hybrid approach that combines configuration interaction and coupled-cluster methods, in good agreement with the experiment. The data are of relevance for understanding the complex atomic spectra of actinides and for developing efficient laser cooling and ionization schemes for actinium, with possible applications for high-purity medical-isotope production and future fundamental physics experiments.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.073001}, author = {Zhang, Ke and Studer, Dominik and Weber, Felix and Gadelshin, Vadim M. and Kneip, Nina and Raeder, Sebastian and Budker, Dmitry and Wendt, Klaus and Kieck, Tom and Porsev, Sergey G. and Cheung, Charles and Safronova, Marianna S. and Kozlov, Mikhail G.} } @article { ISI:000541476900001, title = {Dissipative Kerr Solitons in a III-V Microresonator}, journal = {Laser Photon. Rev.}, volume = {14}, number = {8}, year = {2020}, month = {AUG}, pages = {2000022}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, abstract = {Stable microresonator Kerr soliton frequency combs in a III-V platform (AlGaAs on SiO2) are demonstrated through quenching of thermorefractive effects by cryogenic cooling to temperatures between 4 and 20 K. This cooling reduces the resonator{\textquoteright}s thermorefractive coefficient, whose room-temperature value is an order of magnitude larger than that of other microcomb platforms like Si3N4, SiO2, and AlN, by more than two orders of magnitude, and makes soliton states adiabatically accessible. Realizing such phase-stable soliton operation is critical for applications that fully exploit the ultra-high effective nonlinearity and high optical quality factors exhibited by this platform.}, keywords = {frequency combs, GaAs, microcombs, nanophotonics, Nonlinear optics, soliton}, issn = {1863-8880}, doi = {10.1002/lpor.202000022},}, author = {Moille, Gregory and Chang, Lin and Xie, Weiqiang and Rao, Ashutosh and Lu, Xiyuan and Davanco, Marcelo and Bowers, John E. and Srinivasan, Kartik} } @article { ISI:000530023600007, title = {d-wave superconductivity and Bogoliubov-Fermi surfaces in Rarita-Schwinger-Weyl semimetals}, journal = {Phys. Rev. B}, volume = {101}, number = {18}, year = {2020}, month = {MAY 4}, pages = {184503}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We uncover the properties of complex tensor (d-wave) superconducting order in three-dimensional Rarita-Schwinger-Weyl semimetals that host pseudospin-3/2 fermions at a fourfold linear band-crossing point. Although the general theory of d-wave order was originally developed for materials displaying quadratic band touching, it directly applies to the case of semimetals with linear dispersion, several candidate compounds of which have been discovered experimentally very recently. The spin-3/2 nature of the fermions allows for the formation of spin-2 Cooper pairs which may be described by a complex second-rank tensor order parameter. In the case of linear dispersion, for the chemical potential at the Fermi point and at strong coupling, the energetically preferred superconducting state is the uniaxial nematic state, which preserves time-reversal symmetry and provides a full (anisotropic) gap for quasiparticle excitations. In contrast, at a finite chemical potential, we find that the usual weak-coupling instability is toward the {\textquoteleft}{\textquoteleft}cyclic state,{{\textquoteright}{\textquoteright}} well known from the studies of multicomponent Bose-Einstein condensates, which breaks time-reversal symmetry maximally, has vanishing average value of angular momentum, and features 16 small Bogoliubov-Fermi surfaces. The Rarita-Schwinger-Weyl semimetals provide therefore the first example of weakly coupled, three-dimensional, isotropic d-wave superconductors where the d-wave superconducting phase is uniquely selected by the quartic expansion of the mean-field free energy, and is not afflicted by the accidental degeneracy first noticed by Mermin over 40 years ago. We discuss the appearance and stability of the Bogoliubov-Fermi surfaces in absence of inversion symmetry in the electronic Hamiltonian, as in the case at hand.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.101.184503}, author = {Link, Julia M. and Boettcher, Igor and Herbut, Igor F.} } @article { ISI:000544526900013, title = {Early-Time Exponential Instabilities in Nonchaotic Quantum Systems}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {1}, year = {2020}, month = {JUL 1}, pages = {014101}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The majority of classical dynamical systems are chaotic and exhibit the butterfly effect: a minute change in initial conditions has exponentially large effects later on. But this phenomenon is difficult to reconcile with quantum mechanics. One of the main goals in the field of quantum chaos is to establish a correspondence between the dynamics of classical chaotic systems and their quantum counterparts. In isolated systems in the absence of decoherence, there is such a correspondence in dynamics, but it usually persists only over a short time window, after which quantum interference washes out classical chaos. We demonstrate that quantum mechanics can also play the opposite role and generate exponential instabilities in classically nonchaotic systems within this early-time window. Our calculations employ the out-of-time-ordered correlator (OTOC)-a diagnostic that reduces to the Lyapunov exponent in the classical limit but is well defined for general quantum systems. We show that certain classically nonchaotic models, such as polygonal billiards, demonstrate a Lyapunov-like exponential growth of the OTOC at early times with Planck{\textquoteright}s-constant-dependent rates. This behavior is sharply contrasted with the slow early-time growth of the analog of the OTOC in the systems{\textquoteright} classical counterparts. These results suggest that classical-to-quantum correspondence in dynamics is violated in the OTOC even before quantum interference develops.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.014101}, author = {Rozenbaume, Efim B. and Bunimovich, Leonid A. and Galitski, Victor} } @article {bringewatt_effective_2020, title = {Effective {Gaps} {Are} {Not} {Effective}: {Quasipolynomial} {Classical} {Simulation} of {Obstructed} {Stoquastic} {Hamiltonians}}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {17}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {oct}, abstract = {All known examples suggesting an exponential separation between classical simulation algorithms and stoquastic adiabatic quantum computing (StoqAQC) exploit symmetries that constrain adiabatic dynamics to effective, symmetric subspaces. The symmetries produce large effective eigenvalue gaps, which in turn make adiabatic computation efficient. We present a classical algorithm to subexponentially sample from an effective subspace of any k-local stoquastic Hamiltonian H, without a priori knowledge of its symmetries (or near symmetries). Our algorithm maps any k-local Hamiltonian to a graph G = (V, E) with vertical bar V vertical bar = O(poly(n)), where n is the number of qubits. Given the well-known result of Babai [Graph isomorphism in quasipolynomial time, in Proceedings of the Forty-Eighth Annual ACM Symposium on Theory of Computing (2016), pp. 684-697], we exploit graph isomorphism to study the automorphisms of G and arrive at an algorithm quasipolynomial in vertical bar V vertical bar for producing samples from effective subspace eigenstates of H. Our results rule out exponential separations between StoqAQC and classical computation that arise from hidden symmetries in k-local Hamiltonians. Our graph representation of H is not limited to stoquastic Hamiltonians and may rule out corresponding obstructions in nonstoquastic cases, or be useful in studying additional properties of k-local Hamiltonians.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.170504}, author = {Bringewatt, Jacob and Jarret, Michael} } @conference {lu_efficient_2020-1, title = {Efficient widely-separated optical parametric oscillation}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {We demonstrate the first widely-separated optical parametric oscillation in silicon nanophotonics, with milliwatt-level threshold power that is {\textgreater} 50 times smaller than other widely-separated OPOs. This demonstration is promising for on-chip visible light generation. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Lu, Xiyuan and Moille, Gregory and Singh, Anshuman and Li, Qing and Westly, Daron and Rao, Ashutosh and Yu, Su-Peng and Briles, Travis C. and Drake, Tara and Papp, Scott B. and Srinivasan, Kartik} } @article {mueller_energy-based_2020, title = {Energy-{Based} {Plasmonicity} {Index} to {Characterize} {Optical} {Resonances} in {Nanostructures}}, journal = {J. Phys. Chem. C}, volume = {124}, number = {44, SI}, year = {2020}, note = {Place: 1155 16TH ST, NW, WASHINGTON, DC 20036 USA Publisher: AMER CHEMICAL SOC Type: Article}, month = {nov}, pages = {24331{\textendash}24343}, abstract = {Resonances sustained by plasmonic nanoparticles provide extreme electric field confinement and enhancement into the deep subwavelength domain for a plethora of applications. Recent progress in nanofabrication made it even possible to tailor the properties of nanoparticles consisting of only a few hundred atoms. These nanoparticles support both single-particle-like resonances and collective plasmonic charge density oscillations. Prototypical systems sustaining both features are graphene nanoantennas. In pushing the frontier of nanoscience, traditional identification, and classification of such resonances is at stake again. We show that in such nanostructures, the concerted electron cloud oscillation in real space does not necessarily come along with collective dynamics of conduction band electrons in energy space. This unveils an urgent need for a discussion of how a plasmon in nanostructures should be defined. Here, we propose to define it relying on energy space dynamics. The unambiguous identification of the plasmonic nature of a resonance is crucial to find out whether desirable plasmon-assisted features, such as frequency conversion processes, can be expected from a resonance. We elaborate an energy-based figure of merit that classifies the nature of resonances in nanostructures, motivated by tight binding simulations with a toy model consisting of a linear chain of atoms. We apply afterward the proposed figure of merit to a doped hexagonal graphene nanoantenna, which is known to support plasmons in the near infrared and single-particle-like transitions in the visible.

}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.0c07964}, author = {Mueller, Marvin M. and Kosik, Miriam and Pelc, Marta and Bryant, Garnett W. and Ayuela, Andres and Rockstuhl, Carsten and Slowik, Karolina} } @article {eldredge_entanglement_2020, title = {Entanglement bounds on the performance of quantum computing architectures}, journal = {Phys. Rev. Res.}, volume = {2}, number = {3}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {aug}, abstract = {There are many possible architectures of qubit connectivity that designers of future quantum computers will need to choose between. However, the process of evaluating a particular connectivity graph{\textquoteright}s performance as a quantum architecture can be difficult. In this paper, we show that a quantity known as the isoperimetric number establishes a lower bound on the time required to create highly entangled states. This metric we propose counts resources based on the use of two-qubit unitary operations, while allowing for arbitrarily fast measurements and classical feedback. We use this metric to evaluate the hierarchical architecture proposed by A. Bapat et al. [Phys. Rev. A 98, 062328 (2018)] and find it to be a promising alternative to the conventional grid architecture. We also show that the lower bound that this metric places on the creation time of highly entangled states can be saturated with a constructive protocol, up to a factor logarithmic in the number of qubits.}, doi = {10.1103/PhysRevResearch.2.033316}, author = {Eldredge, Zachary and Zhou, Leo and Bapat, Aniruddha and Garrison, James R. and Deshpande, Abhinav and Chong, Frederic T. and Gorshkov, V, Alexey} } @article { ISI:000562633900003, title = {Exotic Photonic Molecules via Lennard-Jones-like Potentials}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {9}, year = {2020}, month = {AUG 26}, pages = {093601}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Ultracold systems offer an unprecedented level of control of interactions between atoms. An important challenge is to achieve a similar level of control of the interactions between photons. Towards this goal, we propose a realization of a novel Lennard-Jones-like potential between photons coupled to the Rydberg states via electromagnetically induced transparency (EIT). This potential is achieved by tuning Rydberg states to a Forster resonance with other Rydberg states. We consider few-body problems in 1D and 2D geometries and show the existence of self-bound clusters ({{\textquoteright}{\textquoteright}}molecules{{\textquoteright}{\textquoteright}}) of photons. We demonstrate that for a few-body problem, the multibody interactions have a significant impact on the geometry of the molecular ground state. This leads to phenomena without counterparts in conventional systems: For example, three photons in two dimensions preferentially arrange themselves in a line configuration rather than in an equilateral-triangle configuration. Our result opens a new avenue for studies of many-body phenomena with strongly interacting photons.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.093601}, author = {Bienias, Przemyslaw and Gullans, Michael J. and Kalinowski, Marcin and Craddock, Alexander N. and Ornelas-Huerta, Dalia P. and Rolston, S. L. and Porto, V, J. and Gorshkov, V, Alexey} } @article {jabir_experimental_2020, title = {Experimental demonstration of the near-quantum optimal receiver}, journal = {OSA Continuum}, volume = {3}, number = {12}, year = {2020}, note = {Place: 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA Publisher: OPTICAL SOC AMER Type: Article}, month = {dec}, pages = {3324+}, abstract = {We implement the cyclic quantum receiver based on the theoretical proposal of Roy Bondurant and demonstrate experimentally below the shot-noise limit (SNL) discrimination of quadrature phase-shift keying signals (PSK). We also experimentally test the receiver generalized for longer communication alphabet lengths and coherent frequency shift keying (CFSK) encoding. Using off-the-shelf components, we obtain state discrimination error rates that are 3 dB and 4.6 dB below the SNLs of ideal classical receivers for quadrature PSK and CFSK encodings, respectively. The receiver unconditionally surpasses the SNL for M=8 PSK and CFSK. This receiver can be used for the simple and robust practical implementation of quantum-enhanced optical communication. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {2578-7519}, doi = {10.1364/OSAC.409200}, author = {Jabir, V, M. and Burenkov, I. A. and Annafianto, N. Fajar R. and Battou, A. and Polyakov, V, S.} } @article {tenasini_giant_2020, title = {Giant anomalous {Hall} effect in quasi-two-dimensional layered antiferromagnet {Co1}/{3NbS2}}, journal = {Phys. Rev. Res.}, volume = {2}, number = {2}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {apr}, abstract = {The discovery of the anomalous Hall effect (AHE) in bulk metallic antiferromagnets (AFMs) motivates the search of the same phenomenon in two-dimensional (2D) systems, where a quantized anomalous Hall conductance can, in principle, be observed. Here we present experiments on microfabricated devices based on Co1/3NbS2, a layered AFM that was recently found to exhibit AHE in bulk crystals below the Neel temperature T-N = 29 K. Transport measurements reveal a pronounced resistivity anisotropy, indicating that upon lowering temperature the electronic coupling between individual atomic layers is increasingly suppressed. The experiments also show an extremely large anomalous Hall conductivity of approximately 400 S/cm, more than one order of magnitude larger than in the bulk, which demonstrates the importance of studying the AHE in small exfoliated crystals, less affected by crystalline defects. Interestingly, the corresponding anomalous Hall conductance, when normalized to the number of contributing atomic planes, is similar to 0.6 e(2)/h per layer, approaching the value expected for the quantized anomalous Hall effect. The observed strong anisotropy of transport and the very large anomalous Hall conductance per layer make the properties of Co1/3NbS2 compatible with the presence of partially filled topologically nontrivial 2D bands originating from the magnetic superstructure of the antiferromagnetic state. Isolating atomically thin layers of this material and controlling their charge density may therefore provide a viable route to reveal the occurrence of the quantized AHE in a 2D AFM.

}, doi = {10.1103/PhysRevResearch.2.023051}, author = {Tenasini, Giulia and Martino, Edoardo and Ubrig, Nicolas and Ghimire, Nirmal J. and Berger, Helmuth and Zaharko, Oksana and Wu, Fengcheng and Mitchell, J. F. and Martin, Ivar and Forro, Laszlo and Morpurgo, Alberto F.} } @article { ISI:000524530000001, title = {Ground-state energy estimation of the water molecule on a trapped-ion quantum computer}, journal = {npj Quantum Inform.}, volume = {6}, number = {1}, year = {2020}, month = {APR 3}, pages = {33}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {Quantum computing leverages the quantum resources of superposition and entanglement to efficiently solve computational problems considered intractable for classical computers. Examples include calculating molecular and nuclear structure, simulating strongly interacting electron systems, and modeling aspects of material function. While substantial theoretical advances have been made in mapping these problems to quantum algorithms, there remains a large gap between the resource requirements for solving such problems and the capabilities of currently available quantum hardware. Bridging this gap will require a co-design approach, where the expression of algorithms is developed in conjunction with the hardware itself to optimize execution. Here we describe an extensible co-design framework for solving chemistry problems on a trapped-ion quantum computer and apply it to estimating the ground-state energy of the water molecule using the variational quantum eigensolver (VQE) method. The controllability of the trapped-ion quantum computer enables robust energy estimates using the prepared VQE ansatz states. The systematic and statistical errors are comparable to the chemical accuracy, which is the target threshold necessary for predicting the rates of chemical reaction dynamics, without resorting to any error mitigation techniques based on Richardson extrapolation.}, doi = {10.1038/s41534-020-0259-3}, author = {Nam, Yunseong and Chen, Jwo-Sy and Pisenti, Neal C. and Wright, Kenneth and Delaney, Conor and Maslov, Dmitri and Brown, Kenneth R. and Allen, Stewart and Amini, Jason M. and Apisdorf, Joel and Beck, Kristin M. and Blinov, Aleksey and Chaplin, Vandiver and Chmielewski, Mika and Collins, Coleman and Debnath, Shantanu and Hudek, Kai M. and Ducore, Andrew M. and Keesan, Matthew and Kreikemeier, Sarah M. and Mizrahi, Jonathan and Solomon, Phil and Williams, Mike and Wong-Campos, Jaime David and Moehring, David and Monroe, Christopher and Kim, Jungsang} } @article { ISI:000535764500019, title = {Guiding and confining of light in a two-dimensional synthetic space using electric fields}, journal = {Optica}, volume = {7}, number = {5}, year = {2020}, month = {MAY 20}, pages = {506-513}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {Synthetic dimensions provide a promising platform for photonic quantum simulations. Manipulating the flow of photons in these dimensions requires an electric field. However, photons do not have charge and do not directly interact with electric fields. Therefore, alternative approaches are needed to realize electric fields in photonics. One approach is to use engineered gauge fields that can mimic the effect of electric fields and produce the same dynamical behavior. Here, we demonstrate such an electric field for photons propagating in a two-dimensional synthetic space. Generation of electric fields in a two-dimensional synthetic lattice provides the possibility to guide photons and to trap them through the creation of quantum confined structures. We achieve this using a linearly time-varying gauge field generated by direction-dependent phase modulations. We show that the generated electric field leads to Bloch oscillations and the revival of the state after a certain number of steps dependent on the field strength. We measure the probability of the revival and demonstrate a good agreement between the observed values and the theoretically predicted results. Furthermore, by applying a nonuniform electric field, we show the possibility of waveguiding photons. Ultimately, our results open up new opportunities for manipulating the propagation of photons with potential applications in photonic quantum simulations. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {2334-2536}, doi = {10.1364/OPTICA.386347}, author = {Chalabi, Hamidreza and Barik, Sabyasachi and Mittal, Sunil and Murphy, Thomas E. and Hafezi, Mohammad and Waks, Edo} } @article {kuehn_high_2020, title = {High {Resolution} {Photoexcitation} {Measurements} {Exacerbate} the {Long}-{Standing} {Fe} {XVII} {Oscillator} {Strength} {Problem}, journal = {Phys. Rev. Lett.}, volume = {124}, number = {22}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jun}, abstract = {For more than 40 years, most astrophysical observations and laboratory studies of two key soft x-ray diagnostic 2p - 3d transitions, 3C and 3D, in Fe XVII ions found oscillator strength ratios f(3C)/f(3D) disagreeing with theory, but uncertainties had precluded definitive statements on this much studied conundrum. Here, we resonantly excite these lines using synchrotron radiation at PETRA III, and reach, at a millionfold lower photon intensities, a 10 times higher spectral resolution, and 3 times smaller uncertainty than earlier work. Our final result of f(3C)/f(3D) = 3.09(8)(6) supports many of the earlier clean astrophysical and laboratory observations, while departing by five sigmas from our own newest large-scale ab initio calculations, and excluding all proposed explanations, including those invoking nonlinear effects and population transfers.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.124.225001}, author = {Kuehn, Steffen and Shah, Chintan and Lopez-Urrutia, Jose R. Crespo and Fujii, Keisuke and Steinbruegge, Rene and Stierhof, Jakob and Togawa, Moto and Harman, Zoltan and Oreshkina, Natalia S. and Cheung, Charles and Kozlov, Mikhail G. and Porsev, Sergey G. and Safronova, Marianna S. and Berengut, Julian C. and Rosner, Michael and Bissinger, Matthias and Ballhausen, Ralf and Hell, Natalie and Park, SungNam and Chung, Moses and Hoesch, Moritz and Seltmann, Joern and Surzhykov, Andrey S. and Yerokhin, Vladimir A. and Wilms, Joern and Porter, F. Scott and Stoehlker, Thomas and Keitel, Christoph H. and Pfeifer, Thomas and Brown, V, Gregory and Leutenegger, Maurice A. and Bernitt, Sven} } @article {elshaari_hybrid_2020, title = {Hybrid integrated quantum photonic circuits}, journal = {Nat. Photonics}, volume = {14}, number = {5}, year = {2020}, note = {Place: MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND Publisher: NATURE PUBLISHING GROUP Type: Review}, month = {may}, pages = {285{\textendash}298}, abstract = {The Review summarizes the progress of hybrid quantum photonics integration in terms of its important design considerations and fabrication approaches, and highlights some successful realizations of key physical resources for building integrated quantum devices, such as quantum teleporters, quantum repeaters and quantum simulators. Recent developments in chip-based photonic quantum circuits have radically impacted quantum information processing. However, it is challenging for monolithic photonic platforms to meet the stringent demands of most quantum applications. Hybrid platforms combining different photonic technologies in a single functional unit have great potential to overcome the limitations of monolithic photonic circuits. Our Review summarizes the progress of hybrid quantum photonics integration, discusses important design considerations, including optical connectivity and operation conditions, and highlights several successful realizations of key physical resources for building a quantum teleporter. We conclude by discussing the roadmap for realizing future advanced large-scale hybrid devices, beyond the solid-state platform, which hold great potential for quantum information applications.}, issn = {1749-4885}, doi = {10.1038/s41566-020-0609-x}, author = {Elshaari, Ali W. and Pernice, Wolfram and Srinivasan, Kartik and Benson, Oliver and Zwiller, Val} } @article {zhiqiang_hyperfine-mediated_2020, title = {Hyperfine-mediated effects in a {Lu}+ optical clock}, journal = {Phys. Rev. A}, volume = {102}, number = {5}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {nov}, abstract = {We consider hyperfine-mediated effects for clock transitions in Lu-176(+). Mixing of fine-structure levels due to the hyperfine interaction brings about modifications to the Lande g-factors and the quadrupole moment for a given state. Explicit expressions are derived for both the g-factor and quadrupole corrections, for which leading-order terms arise from the nuclear magnetic dipole coupling. High accuracy measurements of the g-factors for the S-1(0) and D-3(1) hyperfine levels are carried out, and they provide an experimental determination of the leading-order correction terms.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.102.052834}, author = {Zhiqiang, Zhang and Arnold, K. J. and Kaewuam, R. and Safronova, M. S. and Barrett, M. D.} } @article {16901, title = {Imaging viscous flow of the Dirac fluid in graphene}, journal = {Nature}, volume = {583}, year = {2020}, month = {Jul}, pages = {537-541}, abstract = {The electron{\textendash}hole plasma in charge-neutral graphene is predicted to realize a quantum critical system in which electrical transport features a universal hydrodynamic description, even at room temperature1,2. This quantum critical {\textquoteleft}Dirac fluid{\textquoteright} is expected to have a shear viscosity close to a minimum bound3,4, with an interparticle scattering rate saturating1 at the Planckian time, the shortest possible timescale for particles to relax. Although electrical transport measurements at finite carrier density are consistent with hydrodynamic electron flow in graphene5{\textendash}8, a clear demonstration of viscous flow at the charge-neutrality point remains elusive. Here we directly image viscous Dirac fluid flow in graphene at room temperature by measuring the associated stray magnetic field. Nanoscale magnetic imaging is performed using quantum spin magnetometers realized with nitrogen vacancy centres in diamond. Scanning single-spin and wide-field magnetometry reveal a parabolic Poiseuille profile for electron flow in a high-mobility graphene channel near the charge-neutrality point, establishing the viscous transport of the Dirac fluid. This measurement is in contrast to the conventional uniform flow profile imaged in a metallic conductor and also in a low-mobility graphene channel. Via combined imaging and transport measurements, we obtain viscosity and scattering rates, and observe that these quantities are comparable to the universal values expected at quantum criticality. This finding establishes a nearly ideal electron fluid in charge-neutral, high-mobility graphene at room temperature4. Our results will enable the study of hydrodynamic transport in quantum critical fluids relevant to strongly correlated electrons in high-temperature superconductors9. This work also highlights the capability of quantum spin magnetometers to probe correlated electronic phenomena at the nanoscale.

}, issn = {1476-4687}, doi = {10.1038/s41586-020-2507-2}, url = {https://doi.org/10.1038/s41586-020-2507-2}, author = {Ku, Mark J. H. and Zhou, Tony X. and Li, Qing and Shin, Young J. and Shi, Jing K. and Burch, Claire and Anderson, Laurel E. and Pierce, Andrew T. and Xie, Yonglong and Hamo, Assaf and Vool, Uri and Zhang, Huiliang and Casola, Francesco and Taniguchi, Takashi and Watanabe, Kenji and Fogler, Michael M. and Kim, Philip and Yacoby, Amir and Walsworth, Ronald L.} } @article { ISI:000575024200001, title = {Infrared fixed points of higher-spin fermions in topological semimetals}, journal = {Phys. Rev. B}, volume = {102}, number = {15}, year = {2020}, month = {OCT 5}, pages = {155104}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We determine the fate of interacting fermions described by the Hamiltonian H = p . J in three-dimensional topological semimetals with linear band crossing, where p is momentum and J are the spin- j matrices for half-integer pseudospin j >= 3/2. While weak short-range interactions are irrelevant at the crossing point due to the vanishing density of states, weak long-range Coulomb interactions lead to a renormalization of the band structure. Using a self-consistent perturbative renormalization group approach, we show that band crossings of the type p . J are unstable for j >= 7/2. Instead, through an intriguing interplay between cubic crystal symmetry, band topology, and interaction effects, the system is attracted to a variety of infrared fixed points. We also unravel several other properties of higher-spin fermions for general j, such as the relation between fermion self-energy and free energy, or the vanishing of the renormalized charge. An O(3) symmetric fixed point composed of equal chirality Weyl fermions is stable for j <= 7/2 and very likely so for all j. We then explore the rich fixed point structure for j = 5/2 in detail. We find additional attractive fixed points with enhanced 0(3) symmetry that host both emergent Weyl or massless Dirac fermions, and identify a puzzling, infrared stable, anisotropic fixed point without enhanced symmetry in close analogy to the known case of j = 3/2.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.102.155104}, author = {Boettcher, Igor} } @article {16956, title = {Instantaneous braids and Dehn twists in topologically ordered states}, journal = {Phys. Rev. B}, volume = {102}, year = {2020}, month = {Aug}, pages = {075105}, doi = {10.1103/PhysRevB.102.075105}, url = {https://link.aps.org/doi/10.1103/PhysRevB.102.075105}, author = {Zhu, Guanyu and Lavasani, Ali and Barkeshli, Maissam} } @conference {rao_integrated_2020, title = {Integrated {Photonic} {Interposers} for {Processing} {Octave}-{Spanning} {Microresonator} {Frequency} {Combs}}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {We demonstrate multiple silicon-nitride nanophotonic elements for on-chip processing of octave-spanning microresonator frequency combs. Dichroic filters, multimode interferometers, and tunable add-drop microring filters are shown along with soliton microcombs generated on a bilayer photonic chip. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Rao, Ashutosh and Moille, Gregory and Lu, Xiyuan and Sacchetto, Davide and Geiselmann, Michael and Zervas, Michael and Papp, Scott and Bowers, John and Srinivasan, Kartik} } @conference {dutta_integrated_2020, title = {An {Integrated} {Photonic} {Platform} for {Rare}-{Earth} {Ions} in {Thin} {Film} {Lithium} {Niobate}}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {We demonstrate an integrated photonic platform for rare earth ions in thin film lithium niobate. The ions in the thin film retain bulk like optical properties. This paves way for a new generation of highly scalable, active optoelectronic devices with applications to both classical and quantum optics. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Dutta, Subhojit and Goldschmidt, Elizabeth A. and Barik, Sabyasachi and Saha, Uday and Waks, Edo} } @article { ISI:000507151600097, title = {Integrated Photonic Platform for Rare-Earth Ions in Thin Film Lithium Niobate}, journal = {Nano Lett.}, volume = {20}, number = {1}, year = {2020}, month = {JAN}, pages = {741-747}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {Rare-earth ion ensembles doped in single crystals are a promising materials system with widespread applications in optical signal processing, lasing, and quantum information processing. Incorporating rare-earth ions into integrated photonic devices could enable compact lasers and modulators, as well as on-chip optical quantum memories for classical and quantum optical applications. To this end, a thin film single crystalline wafer structure that is compatible with planar fabrication of integrated photonic devices would be highly desirable. However, incorporating rare-earth ions into a thin film form-factor while preserving their optical properties has proven challenging. We demonstrate an integrated photonic platform for rare-earth ions doped in a single crystalline thin film lithium niobate on insulator. The thin film is composed of lithium niobate doped with Tm3+. The ions in the thin film exhibit optical lifetimes identical to those measured in bulk crystals. We show narrow spectral holes in a thin film waveguide that require up to 2 orders of magnitude lower power to generate than previously reported bulk waveguides. Our results pave the way for scalable on-chip lasers, optical signal processing devices, and integrated optical quantum memories.}, keywords = {integrated photonics, optical signal processing, Rare-earth ions, spectral hole burning quantum information processing, thin film lithium niobate}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.9b04679}, author = {Dutta, Subhojit and Goldschmidt, Elizabeth A. and Barik, Sabyasachi and Saha, Uday and Waks, Edo} } @article {16681, title = {Interplay of Topology and Electron-Electron Interactions in Rarita-Schwinger-Weyl semimetals}, journal = {Phys. Rev. Lett.}, volume = {124}, year = {2020}, month = {Mar}, pages = {127602}, abstract = {We study, for the first time, the effects of strong short-range electron-electron interactions in generic Rarita-Schwinger-Weyl semimetals hosting spin-3/2\ electrons with linear dispersion at a fourfold band crossing point. The emergence of this novel quasiparticle, which is absent in high-energy physics, has recently been confirmed experimentally in the solid state. We combine symmetry considerations and a perturbative renormalization group analysis to discern three interacting phases that are prone to emerge in the strongly correlated regime: The chiral topological semimetal breaks a\ Z2\ symmetry and features four Weyl nodes of monopole charge\ +1\ located at vertices of a tetrahedron in momentum space. The\ s-wave superconducting state opens a Majorana mass gap for the fermions and is the leading superconducting instability. The Weyl semimetal phase removes the fourfold degeneracy and creates two Weyl nodes with either equal or opposite chirality depending on the anisotropy of the band structure. We find that symmetry breaking occurs at weaker coupling if the total monopole charge remains constant across the transition.

}, doi = {10.1103/PhysRevLett.124.127602}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.124.127602}, author = {Boettcher, Igor} } @article {jian_landau_2020, title = {Landau poles in condensed matter systems}, journal = {Phys. Rev. Res.}, volume = {2}, number = {2}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jun}, abstract = {The existence or not of Landau poles is one of the oldest open questions in nonasymptotic quantum field theories. We investigate the Landau pole issue in two condensed matter systems whose long-wavelength physics is described by appropriate quantum field theories: the critical quantum magnet and Dirac fermions in graphene with long-range Coulomb interactions. The critical quantum magnet provides a classic example of a quantum phase transition, and it is well described by the phi(4) theory. We find that the irrelevant but symmetry-allowed couplings, such as the phi(6) potential, can significantly change the fate of the Landau pole in the emergent phi(4) theory. We obtain the coupled beta functions of a phi(4) + phi(6) potential at both small and large orders. Already from the one-loop calculation, the Landau pole is replaced by an ultraviolet fixed point. A Lipatov analysis at large orders reveals that the inclusion of a phi(6) term also has important repercussions for the high-order expansion of the beta functions. We also investigate the role of the Landau pole in a very different system: Dirac fermions in 2 + 1 dimensions with long-range Coulomb interactions, e.g., graphene. Both the weak-coupling perturbation theory up to two loops and a low-order large-N calculation show the absence of a Landau pole. Furthermore, we calculate the asymptotic expansion coefficients of the beta function. We find that the asymptotic coefficient is bounded by that of a pure bosonic phi(4) theory, and consequently graphene is free from Landau poles if the pure (4) theory does not manifest a Landau pole. We briefly discuss possible experiments that could potentially probe the existence of a Landau pole in these systems. Studying Landau poles in suitable condensed matter systems is of considerable fundamental importance since the relevant Landau pole energy scales in particle physics, whether it is quantum electrodynamics or Higgs physics, are completely unattainable.}, doi = {10.1103/PhysRevResearch.2.023310}, author = {Jian, Shao-Kai and Barnes, Edwin and Das Sarma, Sankar} } @conference {mazurek_loophole-free_2020, title = {Loophole-{Free} {Test} of {Einstein}-{Podolsky}-{Rosen} {Steering} with {One} {Bit} of {Faster}-than-{Light} {Communication}}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {The communication cost for classically simulating Einstein-Podolsky-Rosen (EPR) steering correlations quantifies their strength. We report a loophole-free demonstration of EPR steering correlations requiring more than one faster-than-light bit to simulate. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Mazurek, M. D. and Xiang, Y. and Stevens, M. J. and Bienfang, J. C. and Wayne, M. A. and Abellan, C. and Amaya, W. and Mitchell, M. W. and Mirin, R. P. and Nam, S. W. and He, Q. and Shalm, L. K. and Wiseman, H. M.} } @article { ISI:000527491100005, title = {Magic wavelength of the Ba-138(+) 6s S-2(1/2)-5d D-2(5/2) clock transition}, journal = {Phys. Rev. A}, volume = {101}, number = {4}, year = {2020}, month = {APR 22}, pages = {042507}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The zero crossing of the dynamic differential scalar polarizability of the S-1/2 - D-5/2 clock transition in Ba-138(+) has been determined to be 459.1614(28) THz. Together with previously determined matrix elements and branching ratios, this tightly constrains the dynamic differential scalar polarizability of the clock transition over a large wavelength range (greater than or similar to 700 nm). In particular, it allows an estimate of the blackbody radiation shift of the clock transition at room temperature.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.101.042507}, author = {Chanu, S. R. and Koh, V. P. W. and Arnold, K. J. and Kaewuam, R. and Tan, T. R. and Zhang, Zhiqiang and Safronova, M. S. and Barrett, M. D.} } @article {masson_many-body_2020, title = {Many-{Body} {Signatures} of {Collective} {Decay} in {Atomic} {Chains}}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {26}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, abstract = {Fully inverted atoms placed at exactly the same location synchronize as they deexcite, and light is emitted in a burst (known as {\textquotedblleft}Dicke{\textquoteright}s superradiance{\textquotedblright}). We investigate the role of (mite interatomic separation on correlated decay in mesoscopic chains and provide an understanding in terms of collective jump operators. We show that the superradiant burst survives at small distances, despite Hamiltonian dipole-dipole interactions. However, for larger separations, competition between different jump operators leads to dephasing, suppressing superradiance. Collective effects are still significant for arrays with lattice constants of the order of a wavelength, and lead to a photon emission rate that decays nonexponentially in time. We calculate the two-photon correlation function and demonstrate that emission is correlated and directional, as well as sensitive to small changes in the interatomic distance. These features can be measured in current experimental setups, and are robust to realistic imperfections.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.263601}, author = {Masson, Stuart J. and Ferrier-Barbut, Igor and Orozco, Luis A. and Browaeys, Antoine and Asenjo-Garcia, Ana} } @article { ISI:000505981500001, title = {Many-body localization landscape}, journal = {Phys. Rev. B}, volume = {101}, number = {1}, year = {2020}, month = {JAN 6}, pages = {014201}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We generalize the notion of {\textquoteleft}{\textquoteleft}localization landscape,{{\textquoteright}{\textquoteright}} introduced by M. Filoche and S. Mayboroda {[}Proc. Natl. Acad. Sci. USA 109, 14761 (2012)] for the single-particle Schrodinger operator, to a wide class of interacting many-body Hamiltonians. The many-body localization landscape (MBLL) is defined on a graph in the Fock space, whose nodes represent the basis vectors in the Fock space and edges correspond to transitions between the nodes connected by the hopping term in the Hamiltonian. It is shown that in analogy to the single-particle case, the inverse MBLL plays the role of an effective potential in the Fock space. We construct a generalized discrete Agmon metric and prove Agmon inequalities on the Fock-state graph to obtain bounds on the exponential decay of the many-body wave functions in the Fock space. The corresponding construction is motivated by the semiclassical WKB approximation, but the bounds are exact and fully quantum mechanical. We then prove a series of locality theorems which establish where in the Fock space we expect eigenstates to localize. Using these results as well as the locator expansion, we establish evidence for the existence of many-body localized states for a wide class of lattice models in any physical dimension in at least a part of their Hilbert space. The key to this argument is the observation that in sharp contrast to the conventional locator expansion for the Green{\textquoteright}s function, the locator expansion for the landscape function contains no resonances. For short-range hopping, which limits the connectivity of the Fock-state graph, the locator series is proven to be convergent and bounded by a simple geometric series. This, in combination with the discrete Agmon-type inequalities and the locality theorems, shows that localization for a fraction of the Hilbert space survives weak interactions and weak hopping at least for some realizations of disorder, but cannot prove or rule out localization of the entire Hilbert space. We qualitatively discuss potential breakdown of the locator expansion in the MBLL for long-range hopping and the appearance of a mobility edge in higher-dimensional theories.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.101.014201}, author = {Balasubramanian, Shankar and Liao, Yunxiang and Galitski, Victor} } @article {wu_microwave{\textendash}optical_2020, title = {Microwave-to-{Optical} {Transduction} {Using} a {Mechanical} {Supermode} for {Coupling} {Piezoelectric} and {Optomechanical} {Resonators}}, journal = {Phys. Rev. Appl.}, volume = {13}, number = {1}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {jan}, abstract = {The successes of superconducting quantum circuits at local manipulation of quantum information and photonics technology at long-distance transmission of the same have spurred interest in the development of quantum transducers for efficient, low-noise, and bidirectional frequency conversion of photons between the microwave and optical domains. We propose to realize such functionality through the coupling of electrical, piezoelectric, and optomechanical resonators. The coupling of the mechanical subsystems enables formation of a resonant mechanical supermode that provides a mechanically mediated, efficient single interface to both the microwave and optical domains. The conversion process is analyzed by applying an equivalent circuit model that relates device-level parameters to overall figures of merit for conversion efficiency eta and added noise N. These can be further enhanced by proper impedance matching of the transducer to an input microwave transmission line. The performance of potential transducers is assessed through finite-element simulations, with a focus on geometries in GaAs, followed by considerations of the AlN, LiNbO3, and AlN-on-Si platforms. We present strategies for maximizing eta and minimizing N, and find that simultaneously achieving eta {\textgreater} 50\% and N {\textless} 0.5 should be possible with current technology. We find that the use of a mechanical supermode for mediating transduction is a key enabler for high-efficiency operation, particularly when paired with an appropriate microwave impedance-matching network. Our comprehensive analysis of the full transduction chain enables us to outline a development path for the realization of high-performance quantum transducers that will constitute a valuable resource for quantum information science.

}, issn = {2331-7019}, doi = {10.1103/PhysRevApplied.13.014027}, author = {Wu, Marcelo and Zeuthen, Emil and Balram, Krishna Coimbatore and Srinivasan, Kartik} } @article { ISI:000571399800001, title = {Minimal Model for Fast Scrambling}, journal = {Phys. Rev. Lett.}, volume = {125}, number = {13}, year = {2020}, month = {SEP 21}, pages = {130601}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study quantum information scrambling in spin models with both long-range all-to-all and shortrange interactions. WC argue that a simple global, spatially homogeneous interaction together with local chaotic dynamics is sufficient to give rise to fast scrambling, which describes the spread of quantum information over the entire system in a time that is logarithmic in the system size. This is illustrated in two tractable models: (1) a random circuit with Haar random local unitaties and a global interaction and (2) a classical model of globally coupled nonlinear oscillators. We use exact numerics to provide further evidence by studying the time evolution of an out-of-time-order correlator and entanglement entropy in spin chains of intermediate sizes. Our results pave the way towards experimental investigations of fast scrambling and aspects of quantum gravity with quantum simulators.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.125.130601}, author = {Belyansky, Ron and Bienias, Przemyslaw and Kharkov, Yaroslav A. and Gorshkov, V, Alexey and Swingle, Brian} } @article { ISI:000506845000012, title = {Nonequilibrium nature of nonlinear optical response: Application to the bulk photovoltaic effect}, journal = {Phys. Rev. B}, volume = {101}, number = {4}, year = {2020}, month = {JAN 13}, pages = {045201}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The bulk photovoltaic effect is an example of a nonlinear optical response that leads to a DC current that is relevant for photovoltaic applications. In this paper, we theoretically study this effect in the presence of electron-phonon interactions. Using the response function formalism, we find that the nonlinear optical response, in general, contains three operator correlation functions, one of which is not ordered in time. This latter correlator cannot be computed from equilibrium field theory. Using a semiclassical approach instead, we show that the bulk photovoltaic effect can be attributed to the dipole moment of the generated excitons. We then confirm the validity of the semiclassical result (which agrees with the noninteracting result) for nonlinear DC response from a quantum master equation approach. From this formalism we find that, in contrast to usual linear response, the scattering rate has a strong implicit effect on the nonlinear DC response. Most interestingly, the semiclassical treatment shows that the nonlinear DC response for spatially inhomogeneous excitation profiles is strongly nonlocal and must involve the aforementioned out-of-time-ordered correlators that cannot be computed by equilibrium field theory.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.101.045201}, author = {Barik, Tamoghna and Sau, Jay D.} } @article {reiche_nonequilibrium_2020, title = {Nonequilibrium thermodynamics of quantum friction}, journal = {Phys. Rev. A}, volume = {102}, number = {5}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {nov}, abstract = {Thermodynamic principles are often deceptively simple and yet surprisingly powerful. We show how a simple rule, such as the net flow of energy in and out of a moving atom under a nonequilibrium steady state condition, can expose the shortcomings of many popular theories of quantum friction. Our thermodynamic approach provides a conceptual framework in guiding atom-optical experiments, thereby highlighting the importance of fluctuation-dissipation relations and long-time correlations between subsystems. Our results introduce consistency conditions for (numerical) models of nonequilibrium dynamics of open quantum systems.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.102.050203}, author = {Reiche, D. and Intravaia, F. and Hsiang, J-T and Busch, K. and Hu, B. L.} } @article {hao_nuclear_2020, title = {Nuclear spin-dependent parity-violating effects in light polyatomic molecules}, journal = {Phys. Rev. A}, volume = {102}, number = {5}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {nov}, abstract = {Measurements of nuclear spin-dependent parity-violating (NSD-PV) effects provide an excellent opportunity to test nuclear models and to search for physics beyond the Standard Model. Molecules possess closely spaced states with opposite parity which may be easily tuned to degeneracy to greatly enhance the observed parity-violating effects. A high-sensitivity measurement of NSD-PV effects using light triatomic molecules is in preparation [E. B. Norrgard et al., Common. Phys. 2, 77 (2019)]. Importantly, by comparing these measurements in light nuclei with prior and ongoing measurements in heavier systems, the contribution to NSD-PV from Z(0)-boson exchange between the electrons and the nuclei may be separated from the contribution of the nuclear anapole moment. Furthermore, light triatomic molecules offer the possibility to search for new particles, such as the postulated Z{\textquoteright} boson. In this work, we detail a sensitive measurement scheme and present high-accuracy molecular and nuclear calculations needed for interpretation of NSD-PV experiments on triatomic molecules composed of light elements, Be, Mg, N, and C. The ab initio nuclear structure calculations, performed within the no-core shell model provide a reliable prediction of the magnitude of different contributions to the NSD-PV effects in the four nuclei. These results differ significantly from the predictions of the standard single-particle model and highlight the importance of including many-body effects in such calculations. In order to extract the NSD-PV contributions from measurements, a parity-violating interaction parameter W-PV, which depends on the molecular structure, needs to be known with a high accuracy. We have calculated these parameters for the triatomic molecules of interest using the relativistic coupled-cluster approach. In order to facilitate the interpretation of future experiments we provide uncertainties on the calculated parameters. A scheme for measurement using laser-cooled polyatomic molecules in a molecular fountain is presented, along with an estimate of the expected sensitivity of such an experiment. This experimental scheme, combined with the presented state-of-the-art calculations, opens exciting prospects for a measurement of the anapole moment and the PV effects due to the electron-nucleon interactions with unprecedented accuracy and for a new path towards detection of signatures of physics beyond the Standard Model.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.102.052828}, author = {Hao, Yongliang and Navratil, Petr and Norrgard, Eric B. and Ilias, Miroslav and Eliav, Ephraim and Timmermans, Rob G. E. and Flambaum, Victor V. and Borschevsky, Anastasia} } @article { ISI:000550690300003, title = {On-demand indistinguishable single photons from an efficient and pure source based on a Rydberg ensemble}, journal = {Optica}, volume = {7}, number = {7}, year = {2020}, month = {JUL 20}, pages = {813-819}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {Single photons coupled to atomic systems have shown to be a promising platform for developing quantum technologies. Yet a bright on-demand, highly pure, and highly indistinguishable single-photon source compatible with atomic platforms is lacking. In this work, we demonstrate such a source based on a strongly interacting Rydberg system. The large optical nonlinearities in a blockaded Rydberg ensemble convert coherent light into a single collective excitation that can be coherently retrieved as a quantum field. We simultaneously observe a fully single-mode (spectral, temporal, spatial, and polarization) efficiency up to 0.098(2), a detector-background-subtracted g((2))+5.0(1.6) x 10(-4), and indistinguishability of 0.980(7), at an average photon production rate of 1.18(2) x 10(4) s(-1), All of these make this system promising for scalable quantum information applications. Furthermore, we investigate the effects of contaminant Rydberg excitations on the source efficiency and observed single-mode efficiencies up to 0.18(2) for lower photon rates. Finally, recognizing that many quantum information protocols require a single photon in a fully single mode, we introduce metrics that take into account all degrees of freedom to benchmark the performance of on-demand sources. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {2334-2536}, doi = {10.1364/OPTICA.391485}, author = {Ornelas-Huerta, D. P. and Craddock, A. N. and Goldschmidt, E. A. and Hachtel, A. J. and Wang, Y. and Bienias, P. and Gorshkov, A. V. and Rolston, S. L. and Porto, J. V.} } @article {16931, title = {Photon propagation through dissipative Rydberg media at large input rates}, journal = {Phys. Rev. Research}, volume = {2}, year = {2020}, month = {Jul}, pages = {033049}, abstract = {We study the dissipative propagation of quantized light in interacting Rydberg media under the conditions of electromagnetically induced transparency. Rydberg blockade physics in optically dense atomic media leads to strong dissipative interactions between single photons. The regime of high incoming photon flux constitutes a challenging many-body dissipative problem. We experimentally study in detail the pulse shapes and the second-order correlation function of the outgoing field and compare our data with simulations based on two novel theoretical approaches well-suited to treat this many-photon limit. At low incoming flux, we report good agreement between both theories and the experiment. For higher input flux, the intensity of the outgoing light is lower than that obtained from theoretical predictions. We explain this discrepancy using a simple phenomenological model taking into account pollutants, which are nearly stationary Rydberg excitations coming from the reabsorption of scattered probe photons. At high incoming photon rates, the blockade physics results in unconventional shapes of measured correlation functions.

}, keywords = {Models, Photonics}, doi = {10.1103/PhysRevResearch.2.033049}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.2.033049}, author = {Bienias, Przemyslaw and Douglas, James and Paris-Mandoki, Asaf and Titum, Paraj and Mirgorodskiy, Ivan and Tresp, Christoph and Zeuthen, Emil and Gullans, Michael J. and Manzoni, Marco and Hofferberth, Sebastian and Chang, Darrick and Gorshkov, Alexey V.} } @article { ISI:000555932400003, title = {Probing the relaxed relaxion at the luminosity and precision frontiers}, journal = {J. High Energy Phys.}, number = {7}, year = {2020}, month = {JUL 22}, pages = {153}, publisher = {SPRINGER}, type = {Article}, abstract = {Cosmological relaxation of the electroweak scale is an attractive scenario relaxion, is a light spin-zero field which dynamically relaxes the Higgs mass with respect to its natural large value. We show that the relaxion is generically stabilized at a special position in the field space, which leads to suppression of its mass and potentially unnatural values for the model{\textquoteright}s effective low-energy couplings. In particular, we find that the relaxion mixing with the Higgs can be several orders of magnitude above its naive naturalness bound. Low energy observers may thus find the relaxion theory being fine-tuned although the relaxion scenario itself is constructed in a technically natural way. More generally, we identify the lower and upper bounds on the mixing angle. We examine the experimental implications of the above observations at the luminosity and precision frontiers. A particular attention is given to the impressive ability of future nuclear clocks to search for rapidly oscillating scalar ultra-light dark matter, where the future projected sensitivity is presented.}, keywords = {Beyond Standard Model, Cosmology of Theories beyond the SM}, issn = {1029-8479}, doi = {10.1007/JHEP07(2020)153}, author = {Banerjee, Abhishek and Kim, Hyungjin and Matsedonskyi, Oleksii and Perez, Gilad and Safronova, Marianna S.} } @article {pagano_quantum_2020, title = {Quantum approximate optimization of the long-range {Ising} model with a trapped-ion quantum simulator}, journal = {Proc. Natl. Acad. Sci. U. S. A.}, volume = {117}, number = {41}, year = {2020}, note = {Place: 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA Publisher: NATL ACAD SCIENCES Type: Article}, month = {oct}, pages = {25396{\textendash}25401}, abstract = {Quantum computers and simulators may offer significant advantages over their classical counterparts, providing insights into quantum many-body systems and possibly improving performance for solving exponentially hard problems, such as optimization and satisfiability. Here, we report the implementation of a low-depth Quantum Approximate Optimization Algorithm (QAOA) using an analog quantum simulator. We estimate the ground-state energy of the Transverse Field Ising Model with long-range interactions with tunable range, and we optimize the corresponding combinatorial classical problem by sampling the QAOA output with high-fidelity, single-shot, individual qubit measurements. We execute the algorithm with both an exhaustive search and closed-loop optimization of the variational parameters, approximating the ground-state energy with up to 40 trapped-ion qubits. We benchmark the experiment with bootstrapping heuristic methods scaling polynomially with the system size. We observe, in agreement with numerics, that the QAOA performance does not degrade significantly as we scale up the system size and that the runtime is approximately independent from the number of qubits. We finally give a comprehensive analysis of the errors occurring in our system, a crucial step in the path forward toward the application of the QAOA to more general problem instances.}, keywords = {computing, quantum, quantum algorithms, quantum information science, quantum simulation, trapped ions}, issn = {0027-8424}, doi = {10.1073/pnas.2006373117}, author = {Pagano, Guido and Bapat, Aniruddha and Becker, Patrick and Collins, Katherine S. and De, Arinjoy and Hess, Paul W. and Kaplan, Harvey B. and Kyprianidis, Antonis and Tan, Wen Lin and Baldwin, Christopher and Brady, Lucas T. and Deshpande, Abhinav and Liu, Fangli and Jordan, Stephen and Gorshkov, V, Alexey and Monroe, Christopher} } @article {zhu_quantum_2020, title = {Quantum origami: {Transversal} gates for quantum computation and measurement of topological order}, journal = {Phys. Rev. Res.}, volume = {2}, number = {1}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {mar}, abstract = {In topology, a torus remains invariant under certain nontrivial transformations known as modular transformations. In the context of topologically ordered quantum states of matter supported on a torus geometry in real space, these transformations encode the braiding statistics and fusion rules of emergent anyonic excitations and thus serve as a diagnostic of topological order. Moreover, modular transformations of higher genus surfaces, e.g., a torus with multiple handles, can enhance the computational power of a topological state, in many cases providing a universal fault-tolerant set of gates for quantum computation. However, due to the intrusive nature of modular transformations, which abstractly involve global operations, physical implementations of them in local systems have remained elusive. Here, we show that by engineering an effectively folded manifold corresponding to a multilayer topological system, modular transformations can be applied in a single shot by independent local unitaries, providing a novel class of transversal logical gates for fault-tolerant quantum computation. Specifically, we demonstrate that multilayer topological states with appropriate boundary conditions and twist defects allow modular transformations to be effectively implemented by a finite sequence of local SWAP gates between the layers. We further provide methods to directly measure the modular matrices, and thus the fractional statistics of anyonic excitations, providing a novel way to directly measure topological order. A more general theory of transversal gates and the deep connection to anyon symmetry transformation and symmetry-enriched topological orders are also discussed.}, doi = {10.1103/PhysRevResearch.2.013285}, author = {Zhu, Guanyu and Hafezi, Mohammad and Barkeshli, Maissam} } @article { ISI:000570957900002, title = {Quantum oscillations from networked topological interfaces in a Weyl semimetal}, journal = {npj Quantum Mater.}, volume = {5}, number = {1}, year = {2020}, month = {SEP 7}, pages = {62}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {Layered transition metal chalcogenides are promising hosts of electronic Weyl nodes and topological superconductivity. MoTe(2)is a striking example that harbors both noncentrosymmetric T(d)and centrosymmetric T{\textquoteright} phases, both of which have been identified as topologically nontrivial. Applied pressure tunes the structural transition separating these phases to zero temperature, stabilizing a mixed T-d-T{\textquoteright} matrix that entails a network of interfaces between the two nontrivial topological phases. Here, we show that this critical pressure range is characterized by distinct coherent quantum oscillations, indicating that the difference in topology between topologically nonvtrivial T(d)and T{\textquoteright} phases gives rise to an emergent electronic structure: a network of topological interfaces. A rare combination of topologically nontrivial electronic structures and locked-in transformation barriers leads to this counterintuitive situation, wherein quantum oscillations can be observed in a structurally inhomogeneous material. These results further open the possibility of stabilizing multiple topological phases coexisting with superconductivity.}, doi = {10.1038/s41535-020-00264-8}, author = {Liu, I-Lin and Heikes, Colin and Yildirim, Taner and Eckberg, Chris and Metz, Tristin and Kim, Hyunsoo and Ran, Sheng and Ratcliff, William D. and Paglione, Johnpierre and Butch, Nicholas P.} } @article {17096, title = {Quantum simulation of hyperbolic space with circuit quantum electrodynamics: From graphs to geometry}, journal = {Phys. Rev. A}, volume = {102}, year = {2020}, month = {Sep}, pages = {032208}, abstract = {We show how quantum many-body systems on hyperbolic lattices with nearest-neighbor hopping and local interactions can be mapped onto quantum field theories in continuous negatively curved space. The underlying lattices have recently been realized experimentally with superconducting resonators and therefore allow for a table-top quantum simulation of quantum physics in curved background. Our mapping provides a computational tool to determine observables of the discrete system even for large lattices, where exact diagonalization fails. As an application and proof of principle we quantitatively reproduce the ground state energy, spectral gap, and correlation functions of the noninteracting lattice system by means of analytic formulas on the Poincar{\'e} disk, and show how conformal symmetry emerges for large lattices. This sets the stage for studying interactions and disorder on hyperbolic graphs in the future. Importantly, our analysis reveals that even relatively small discrete hyperbolic lattices emulate the continuous geometry of negatively curved space, and thus can be used to experimentally resolve fundamental open problems at the interface of interacting many-body systems, quantum field theory in curved space, and quantum gravity.

}, keywords = {hyperbolic geometry, quantum simulation}, doi = {10.1103/PhysRevA.102.032208}, url = {https://link.aps.org/doi/10.1103/PhysRevA.102.032208}, author = {Boettcher, Igor and Bienias, Przemyslaw and Belyansky, Ron and Kollar, Alicia J. and Gorshkov, Alexey V.} } @article { ISI:000556360300013, title = {Quantum walks and Dirac cellular automata on a programmable trapped-ion quantum computer}, journal = {Nat. Commun.}, volume = {11}, number = {1}, year = {2020}, month = {JUL 24}, pages = {3720}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {The quantum walk formalism is a widely used and highly successful framework for modeling quantum systems, such as simulations of the Dirac equation, different dynamics in both the low and high energy regime, and for developing a wide range of quantum algorithms. Here we present the circuit-based implementation of a discrete-time quantum walk in position space on a five-qubit trapped-ion quantum processor. We encode the space of walker positions in particular multi-qubit states and program the system to operate with different quantum walk parameters, experimentally realizing a Dirac cellular automaton with tunable mass parameter. The quantum walk circuits and position state mapping scale favorably to a larger model and physical systems, allowing the implementation of any algorithm based on discrete-time quantum walks algorithm and the dynamics associated with the discretized version of the Dirac equation.}, issn = {2041-1723}, doi = {10.1038/s41467-020-17519-4}, author = {Alderete, C. Huerta and Singh, Shivani and Nhung H Nguyen and Zhu, Daiwei and Balu, Radhakrishnan and Monroe, Christopher and Chandrashekar, C. M. and Linke, Norbert M.} } @article { ISI:000555323500001, title = {Quenched vs Annealed: Glassiness from SK to SYK}, journal = {Phys. Rev. X}, volume = {10}, number = {3}, year = {2020}, month = {AUG 4}, pages = {031026}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We show that any Sachdev-Ye-Kitaev- (SYK) like model with finite-body interactions among local degrees of freedom, e.g., bosons or spins, has a fundamental difference from the standard fermionic model: The former model fails to be described by an annealed free energy at low temperature. In this respect, such models more closely resemble spin glasses. We demonstrate this by two means: first, a general theorem proving that the annealed free energy is divergent at low temperature in any model with a tensor product Hilbert space, and second, a replica treatment of two prominent examples which exhibit phase transitions from an {\textquoteleft}{\textquoteleft}annealed{{\textquoteright}{\textquoteright}} phase to a {\textquoteleft}{\textquoteleft}nonannealed{{\textquoteright}{\textquoteright}} phase as a function of the temperature. We further show that this effect appears only at O(N)th order in a 1/N expansion, even though lower-order terms misleadingly seem to converge. Our results prove that the nonbosonic nature of the particles in the SYK model is an essential ingredient for its physics, highlight connections between local models and spin glasses, and raise important questions as to the role of fermions and/or glassiness in holography.}, issn = {2160-3308}, doi = {10.1103/PhysRevX.10.031026}, author = {Baldwin, C. L. and Swingle, B.} } @article {barker_radiofrequency_2020, title = {A radiofrequency voltage-controlled current source for quantum spin manipulation}, journal = {Rev. Sci. Instrum.}, volume = {91}, number = {10}, year = {2020}, note = {Place: 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA Publisher: AMER INST PHYSICS Type: Article}, month = {oct}, abstract = {We present a wide-bandwidth, voltage-controlled current source that is easily integrated with radiofrequency magnetic field coils. Our design uses current feedback to compensate for the frequency-dependent impedance of a radiofrequency antenna. We are able to deliver peak currents greater than 100 mA over a 300 kHz to 54 MHz frequency span. The radiofrequency current source fits onto a printed circuit board smaller than 4 cm(2) and consumes less than 1.3 W of power. It is suitable for use in deployable quantum sensors and nuclear magnetic resonance systems.}, issn = {0034-6748}, doi = {10.1063/5.0011813}, author = {Barker, D. S. and Restelli, A. and Fedchak, J. A. and Scherschligt, J. and Eckel, S.} } @article { ISI:000527910200017, title = {Reflection and Time Reversal Symmetry Enriched Topological Phases of Matter: Path Integrals, Non-orientable Manifolds, and Anomalies}, journal = {Commun. Math. Phys.}, volume = {374}, number = {2}, year = {2020}, month = {MAR}, pages = {1021-1124}, publisher = {SPRINGER}, type = {Article}, abstract = {We study symmetry-enriched topological (SET) phases in 2+1 space-time dimensions with spatial reflection and/or time-reversal symmetries. We provide a systematic construction of a wide class of reflection and time-reversal SET phases in terms of a topological path integral defined on general space-time manifolds. An important distinguishing feature of different topological phases with reflection and/or time-reversal symmetry is the value of the path integral on non-orientable space-time manifolds. We derive a simple general formula for the path integral on the manifold Sigma(2) x S-1, where Sigma(2) is a two-dimensional non-orientable surface and S-1 is a circle. This also gives an expression for the ground state degeneracy of the SET on the surface Sigma(2) that depends on the reflection symmetry fractionalization class, generalizing the Verlinde formula for ground state degeneracy on orientable surfaces. Consistency of the action of the mapping class group on non-orientable manifolds leads us to a constraint that can detect when a time-reversal or reflection SET phase is anomalous in (2+1)D and, thus, can only exist at the surface of a (3+1)D symmetry protected topological (SPT) state. Given a (2+1)D reflection and/or time-reversal SET phase, we further derive a general formula that determines which (3+1)D reflection and/or time-reversal SPT phase hosts the (2+1)D SET phase as its surface termination. A number of explicit examples are studied in detail.}, issn = {0010-3616}, doi = {10.1007/s00220-019-03475-8}, author = {Barkeshli, Maissam and Bonderson, Parsa and Cheng, Meng and Jian, Chao-Ming and Walker, Kevin} } @article {barkeshli_relative_2020, title = {Relative anomalies in (2+1){D} symmetry enriched topological states}, journal = {SciPost Phys.}, volume = {8}, number = {2}, year = {2020}, note = {Place: C/O J S CAUX, INST PHYSICS, UNIV AMSTERDAM, AMSTERDAM, 1098 XH, NETHERLANDS Publisher: SCIPOST FOUNDATION Type: Article}, month = {feb}, abstract = {Certain patterns of symmetry fractionalization in topologically ordered phases of matter are anomalous, in the sense that they can only occur at the surface of a higher dimensional symmetry-protected topological (SPT) state. An important question is to determine how to compute this anomaly, which means determining which SPT hosts a given symmetry-enriched topological order at its surface. While special cases are known, a general method to compute the anomaly has so far been lacking. In this paper we propose a general method to compute relative anomalies between different symmetry fractionalization classes of a given (2+1)D topological order. This method applies to all types of symmetry actions, including anyon-permuting symmetries and general space-time reflection symmetries. We demonstrate compatibility of the relative anomaly formula with previous results for diagnosing anomalies for Z(2)(T) space-time reflection symmetry (e.g. where time-reversal squares to the identity) and mixed anomalies for U(1) x Z(2)(T) and U (1) (sic) Z(2)(T) symmetries. We also study a number of additional examples, including cases where space-time reflection symmetries are intertwined in non-trivial ways with unitary symmetries, such as Z(4)(T) and mixed anomalies for Z(2) x Z(2)(T) symmetry, and unitary Z(2) x Z(2) symmetry with non-trivial anyon permutations.}, issn = {2542-4653}, doi = {10.21468/SciPostPhys.8.2.028}, author = {Barkeshli, Maissam and Cheng, Meng} } @article {brewer_signal_2020, title = {Signal advance and delay due to an optical phase-sensitive amplifier}, journal = {Opt. Express}, volume = {28}, number = {10}, year = {2020}, note = {Place: 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA Publisher: OPTICAL SOC AMER Type: Article}, month = {may}, pages = {14573{\textendash}14579}, abstract = {Fast and slow light media exploit a steep frequency dependence in their index of refraction in order to advance or delay a modulated signal. Here we observe a qualitatively similar advance and delay from an optical phase-sensitive amplifier (PSA). Unlike in the case of slow and fast light, this effect is due to a redistribution of power between imbalanced signal sidebands, and the advance or delay is dependent on the optical phase of the input. The PSA adds energy and also changes the frequency spectrum of the input. We show that the advances and delays observed in a PSA implemented using four-wave mixing in a warm rubidium vapor are consistent with the expected behavior of an ideal PSA.}, issn = {1094-4087}, doi = {10.1364/OE.392789}, author = {Brewer, Nicholas R. and Li, Tian and Jones, Kevin M. and Lett, Paul D.} } @conference {sabines-chesterking_single-emitter-sensitivity_2020, title = {Single-emitter-sensitivity in flow cytometry verified by quantum measurement}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {We demonstrate single quantum emitter sensitivity in a flow cytometer by measuring the second order correlation function to be g((2))(0) = 0.5(1). (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Sabines-Chesterking, Javier and Burenkov, Ivan A. and Polyakov, V, Sergey} } @conference {moille_stable_2020, title = {Stable {Dissipative} {Kerr} {Solitons} in a {AlGaAs} {Microresonator} {Through} {Cryogenic} {Operation}}, booktitle = {Conference on Lasers and Electro-Optics (CLEO)}, series = {Conference on {Lasers} and {Electro}-{Optics}}, year = {2020}, note = {Backup Publisher: IEEE ISSN: 2160-9020 Type: Proceedings Paper}, publisher = {IEEE}, organization = {IEEE}, abstract = {We demonstrate stable microresonator Kerr solitons in an Al0.2Ga0.8As-on-insulator resonator thanks to cryogenic quenching of the thermorefractive effect. Reaching such a phase-stable state is a prerequisite to fully exploit the potential of this platform. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Moille, Gregory and Chang, Lin and Xie, Weiqiang and Lu, Xiyuan and Davanco, Marcelo and Bowers, John E. and Srinivasan, Kartik} } @article { ISI:000533504100003, title = {State-Dependent Optical Lattices for the Strontium Optical Qubit}, journal = {Phys. Rev. Lett.}, volume = {124}, number = {20}, year = {2020}, month = {MAY 18}, pages = {203201}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We demonstrate state-dependent optical lattices for the Sr optical qubit at the tune-out wavelength for its ground state. We tightly trap excited state atoms while suppressing the effect of the lattice on ground state atoms by more than 4 orders of magnitude. This highly independent control over the qubit states removes inelastic excited state collisions as the main obstacle for quantum simulation and computation schemes based on the Sr optical qubit. Our results also reveal large discrepancies in the atomic data used to calibrate the largest systematic effect of Sr optical lattice clocks.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.124.203201}, author = {Heinz, A. and Park, A. J. and Santi, N. and Trautmann, J. and Porsev, S. G. and Safronova, M. S. and Bloch, I and Blatt, S.} } @article {19026, title = {Symmetry Breaking and Error Correction in Open Quantum Systems}, journal = {Phys. Rev. Lett.}, volume = {125}, year = {2020}, month = {Dec}, pages = {240405}, abstract = {Symmetry-breaking transitions are a well-understood phenomenon of closed quantum systems in quantum optics, condensed matter, and high energy physics. However, symmetry breaking in open systems is less thoroughly understood, in part due to the richer steady-state and symmetry structure that such systems possess. For the prototypical open system{\textemdash}a Lindbladian{\textemdash}a unitary symmetry can be imposed in a {\textquotedblleft}weak{\textquotedblright} or a {\textquotedblleft}strong{\textquotedblright} way. We characterize the possible\ Zn\ symmetry-breaking transitions for both cases. In the case of\ Z2, a weak-symmetry-broken phase guarantees at most a classical bit steady-state structure, while a strong-symmetry-broken phase admits a partially protected steady-state qubit. Viewing photonic cat qubits through the lens of strong-symmetry breaking, we show how to dynamically recover the logical information after any gap-preserving strong-symmetric error; such recovery becomes perfect exponentially quickly in the number of photons. Our study forges a connection between driven-dissipative phase transitions and error correction.

}, doi = {10.1103/PhysRevLett.125.240405}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.125.240405}, author = {Lieu, Simon and Belyansky, Ron and Young, Jeremy T. and Lundgren, Rex and Albert, Victor V. and Gorshkov, Alexey V.} } @article {17056, title = {Time-Resolving Quantum Measurement Enables Energy-Efficient, Large-Alphabet Communication}, journal = {PRX Quantum}, volume = {1}, year = {2020}, month = {Sep}, pages = {010308}, doi = {10.1103/PRXQuantum.1.010308}, url = {https://link.aps.org/doi/10.1103/PRXQuantum.1.010308}, author = {Burenkov, I.A. and Jabir, M.V. and Battou, A. and Polyakov, S.V.} } @article {aasen_topological_2020, title = {Topological defect networks for fractons of all types}, journal = {Phys. Rev. Res.}, volume = {2}, number = {4}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, abstract = {Fracton phases exhibit striking behavior which appears to render them beyond the standard topological quantum field theory (TQFT) paradigm for classifying gapped quantum matter. Here, we explore fracton phases from the perspective of defect TQFTs and show that topological defect networks-networks of topological defects embedded in stratified 3+1-dimensional (3+1D) TQFTs-provide a unified framework for describing various types of gapped fracton phases. In this picture, the subdimensional excitations characteristic of fractonic matter are a consequence of mobility restrictions imposed by the defect network. We conjecture that all gapped phases, including fracton phases, admit a topological defect network description and support this claim by explicitly providing such a construction for many well-known fracton models, including the X-cube and Haah{\textquoteright}s B code. To highlight the generality of our framework, we also provide a defect network construction of a fracton phase hosting non-Abelian fractons. As a byproduct of this construction, we obtain a generalized membrane-net description for fractonic ground states as well as an argument that our conjecture implies no topological fracton phases exist in 2+1-dimensional gapped systems. Our paper also sheds light on techniques for constructing higher-order gapped boundaries of 3+1D TQFTs.}, doi = {10.1103/PhysRevResearch.2.043165}, author = {Aasen, David and Bulmash, Daniel and Prem, Abhinav and Slagle, Kevin and Williamson, Dominic J.} } @article {bienias_two_2020, title = {Two photon conditional phase gate based on {Rydberg} slow light polaritons}, journal = {J. Phys. B-At. Mol. Opt. Phys.}, volume = {53}, number = {5}, year = {2020}, note = {Place: TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND Publisher: IOP PUBLISHING LTD Type: Article}, month = {mar}, abstract = {We analyze the fidelity of a deterministic quantum phase gate (QPG) for two photons counterpropagating as polaritons through a cloud of Rydberg atoms under the condition of electromagnetically induced transparency (EIT). We provide analytical results for the phase shift of the quantum gate, and provide an estimation for all processes leading to a reduction to the gate fidelity. Especially, the influence of losses from the intermediate level, dispersion of the photon wave packet, scattering into additional polariton channels, finite lifetime of the Rydberg state, as well as effects of transverse size of the wave packets are accounted for. We show that the flatness of the effective interaction, caused by the blockade phenomena, suppresses the corrections due to the finite transversal size. This is a strength of Rydberg-EIT setup compared to other approaches. Finally, we provide the experimental requirements for the realization of a high fidelity QPG using Rydberg polaritons.}, keywords = {amo, quantum gate, Quantum optics, Rydberg polaritons, Rydbergs}, issn = {0953-4075}, doi = {10.1088/1361-6455/ab5bed}, author = {Bienias, Przemyslaw and Buechler, Hans Peter} } @article { ISI:000562002100002, title = {Two-dimensional electron self-energy: Long-range Coulomb interaction}, journal = {Phys. Rev. B}, volume = {102}, number = {8}, year = {2020}, month = {AUG 24}, pages = {085145}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The electron self-energy for long-range Coulomb interactions plays a crucial role in understanding the many-body physics of interacting electron systems (e.g., in metals and semiconductors) and has been studied extensively for decades. In fact, it is among the oldest and the most-investigated many-body problems in physics. However, there is a lack of an analytical expression for the self-energy Re Sigma((R)) (epsilon, T) when energy epsilon and temperature k(B)T are arbitrary with respect to each other (while both being still small compared with the Fermi energy). We revisit this problem and calculate analytically the self-energy on the mass shell for a two-dimensional electron system with Coulomb interactions in the high density limit r(s)<< 1, for temperature r(s)(3/2) << k(B)T/E-F << r(s) and energy r(s)(3/2) << vertical bar epsilon vertical bar << r(s). We provide the exact high-density analytical expressions for the real and imaginary parts of the electron self-energy with arbitrary value of epsilon/KBT, to the leading order in the dimensionless Coulomb coupling constant r(s), and to several higher than leading orders in k(B)T/r(s)E(F) and epsilon/r(s)E(F) . We also obtain the asymptotic behavior of the self-energy in the regimes vertical bar epsilon vertical bar << k(B)T and vertical bar epsilon vertical bar >> k(B)T. The higher-order terms have subtle and highly nontrivial compound logarithmic contributions from both epsilon and T, explaining why they have never before been calculated in spite of the importance of the subject matter.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.102.085145}, author = {Liao, Yunxiang and Buterakos, Donovan and Schecter, Mike and Das Sarma, Sankar} } @article { ISI:000515320000001, title = {Type II Photoinitiator and Tuneable Poly(Ethylene Glycol)-Based Materials Library for Visible Light Photolithography}, journal = {Tissue Eng. Part A}, volume = {26}, number = {5-6}, year = {2020}, month = {MAR 1}, pages = {292-304}, publisher = {MARY ANN LIEBERT, INC}, type = {Article}, abstract = {Stereolithography (SL) has several advantages over traditional biomanufacturing techniques such as fused deposition modeling, including increased speed, accuracy, and efficiency. While SL has been broadly used in tissue engineering for the fabrication of three-dimensional scaffolds that can mimic the in vivo environment for cell growth and tissue regeneration, lithographic printing is usually performed on single-component materials cured with ultraviolet light, severely limiting the versatility and cytocompatibility of such systems. In this study, we report a highly tunable, low-cost photoinitiator system that we used to establish a systematic library of crosslinked materials based on low molecular weight poly(ethylene glycol) diacrylate. We assessed the physicochemical properties, photocrosslinking efficiency, cost performance, and biocompatibility to demonstrate the capability of manufacturing a multimaterial complex tissue scaffold.

}, keywords = {bioink, multimaterial scaffold, photocrosslinkable hydrogel, poly(ethylene glycol) diacrylate (PEG-DA), stereolithography, visible light type II photoinitiator}, issn = {1937-3341}, doi = {10.1089/ten.tea.2019.0282},}, author = {Yang, Xin and Mohseni, Mina and Bas, Onur and Meinert, Christoph and New, Elizabeth J. and Castro, Nathan J.} } @article {16951, title = {Universal Logical Gates on Topologically Encoded Qubits via Constant-Depth Unitary Circuits}, journal = {Phys. Rev. Lett.}, volume = {125}, year = {2020}, month = {Jul}, pages = {050502}, doi = {10.1103/PhysRevLett.125.050502}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.125.050502}, author = {Zhu, Guanyu and Lavasani, Ali and Barkeshli, Maissam} } @article {balram_zn_2020, title = {Z(n) superconductivity of composite bosons and the 7/3 fractional quantum {Hall} effect}, journal = {Phys. Rev. Res.}, volume = {2}, number = {1}, year = {2020}, note = {Place: ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA Publisher: AMER PHYSICAL SOC Type: Article}, month = {mar}, abstract = {The topological p-wave pairing of composite fermions, believed to be responsible for the 5/2 fractional quantum Hall effect (FQHE), has generated much exciting physics. Motivated by the parton theory of the FQHE, we consider the possibility of a new kind of emergent {\textquotedblleft}superconductivity{\textquotedblright} in the 1/3 FQHE, which involves condensation of clusters of n composite bosons. From a microscopic perspective, the state is described by the n (n) over bar 111 parton wave function P-LLL Phi(n)Phi(n)*Phi(3)(1), where Phi(n) is the wave function of the integer quantum Hall state with n filled Landau levels and P-LLL is the lowest-Landau-level projection operator. It represents a Z(n) superconductor of composite bosons, because the factor Phi(3)(1) similar to Pi(j{\textless}k) (z(j) - z(k))(3), where z(j) = x(j) - iy(j) is the coordinate of the jth electron, binds three vortices to electrons to convert them into composite bosons, which then condense into the Z(n) superconducting state vertical bar Phi(n)vertical bar(2). From a field theoretical perspective, this state can be understood by starting with the usual Laughlin theory and gauging a Z(n) subgroup of the U(1) charge conservation symmetry. We find from detailed quantitative calculations that the 2{\textless}(2)over bar{\textgreater}111 and 3 (3) over bar 111 states are at least as plausible as the Laughlin wave function for the exact Coulomb ground state at filling nu = 7/3, suggesting that this physics is possibly relevant for the 7/3 FQHE. The Z(n) order leads to several observable consequences, including quasiparticles with fractionally quantized charges of magnitude e/(3n) and the existence of multiple neutral collective modes. It is interesting that the FQHE may be a promising venue for the realization of exotic Z(n) superconductivity.}, doi = {10.1103/PhysRevResearch.2.013349}, author = {Balram, Ajit C. and Jain, J. K. and Barkeshli, Maissam} } @article { ISI:000501768100003, title = {Additive biomanufacturing of scaffolds for breast reconstruction}, journal = {Addit. Manuf.}, volume = {30}, year = {2019}, month = {DEC}, pages = {UNSP 100845}, publisher = {ELSEVIER}, type = {Article}, abstract = {Limitations for the current clinical treatment strategies for breast reconstruction have prompted researchers and bioengineers to develop unique techniques based on tissue engineering and regenerative medicine (TE\&RM) principles. Recently, scaffold-guided soft TE has emerged as a promising approach due to its potential to modulate the process of tissue regeneration. Herein, we utilized additive biomanufacturing (ABM) to develop an original design-based concept for scaffolds which can be applied in TE-based breast reconstruction procedures. The scaffold design addresses biomechanical and biological requirements for medium to large-volume regeneration with the potential of customization. The model is composed of two independent structural components. The external structure provides biomechanical stability to minimize load transduction to the newly formed tissue while the internal structure provides a large pore and fully interconnected pore architecture to facilitate tissue regeneration. A methodology was established to design, optimize and 3D print the external structure with customized biomechanical properties. The internal structure was also designed and printed with a gradient of pore size and a channel structure to facilitate lipoaspirated fat delivery and entrapment. A fused filament fabrication-based printing strategy was employed to print two structures as a monolithic breast implant.}, keywords = {Additive biomanufacturing, Breast implant customization, In silico modelling, Scaffolds}, issn = {2214-8604}, doi = {10.1016/j.addma.2019.100845}, author = {Mohseni, Mina and Bas, Onur and Castro, Nathan J. and Schmutz, Beat and Hutmacher, Dietmar W.} } @article {13366, title = {Alignment-dependent decay rate of an atomic dipole near an optical nanofiber}, journal = {Phys. Rev. A}, volume = {99}, year = {2019}, month = {Jan}, pages = {013822}, doi = {10.1103/PhysRevA.99.013822}, url = {https://link.aps.org/doi/10.1103/PhysRevA.99.013822}, author = {Solano, P. and Grover, J. A. and Xu, Y. and Barberis-Blostein, P. and Munday, J. N. and Orozco, L. A. and Phillips, W. D. and Rolston, S. L.} } @article { ISI:000500475200001, title = {Benchmarking an 11-qubit quantum computer}, journal = {Nat. Commun.}, volume = {10}, year = {2019}, month = {NOV 29}, pages = {5464}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {The field of quantum computing has grown from concept to demonstration devices over the past 20 years. Universal quantum computing offers efficiency in approaching problems of scientific and commercial interest, such as factoring large numbers, searching databases, simulating intractable models from quantum physics, and optimizing complex cost functions. Here, we present an 11-qubit fully-connected, programmable quantum computer in a trapped ion system composed of 13 Yb-171(+) ions. We demonstrate average single-qubit gate fidelities of 99.5\%, average two-qubit-gate fidelities of 97.5\%, and SPAM errors of 0.7\%. To illustrate the capabilities of this universal platform and provide a basis for comparison with similarly-sized devices, we compile the Bernstein-Vazirani and Hidden Shift algorithms into our native gates and execute them on the hardware with average success rates of 78\% and 35\%, respectively. These algorithms serve as excellent benchmarks for any type of quantum hardware, and show that our system outperforms all other currently available hardware.}, issn = {2041-1723}, doi = {10.1038/s41467-019-13534-2}, author = {Wright, K. and Beck, K. M. and Debnath, S. and Amini, J. M. and Nam, Y. and Grzesiak, N. and Chen, J. -S. and Pisenti, N. C. and Chmielewski, M. and Collins, C. and Hudek, K. M. and Mizrahi, J. and Wong-Campos, J. D. and Allen, S. and Apisdorf, J. and Solomon, P. and Williams, M. and Ducore, A. M. and Blinov, A. and Kreikemeier, S. M. and Chaplin, V. and Keesan, M. and Monroe, C. and Kim, J.} } @article {ISI:000461964300002, title = {Braiding and gapped boundaries in fracton topological phases}, journal = {Phys. Rev. B}, volume = {99}, number = {12}, year = {2019}, month = {MAR 19}, pages = {125132}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study gapped boundaries of Abelian type-I fracton systems in three spatial dimensions. Using the X-cube model as our motivating example, we give a conjecture, with partial proof, of the conditions for a boundary to be gapped. In order to state our conjecture, we use a precise definition of fracton braiding and show that bulk braiding of fractons has several features that make it insufficient to classify gapped boundaries. Most notable among these is that bulk braiding is sensitive to geometry and is {\textquoteleft}{\textquoteleft}nonreciprocal{{\textquoteright}{\textquoteright}}; that is, braiding an excitation a around b need not yield the same phase as braiding b around a. Instead, we define fractonic {\textquoteleft}{\textquoteleft}boundary braiding,{{\textquoteright}{\textquoteright}} which resolves these difficulties in the presence of a boundary. We then conjecture that a boundary of an Abelian fracton system is gapped if and only if a {\textquoteleft}{\textquoteleft}boundary Lagrangian subgroup{{\textquoteright}{\textquoteright}} of excitations is condensed at the boundary; this is a generalization of the condition for a gapped boundary in two spatial dimensions, but it relies on boundary braiding instead of bulk braiding. We also discuss the distinctness of gapped boundaries and transitions between different topological orders on gapped boundaries.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.125132}, author = {Bulmash, Daniel and Iadecola, Thomas} } @conference {ISI:000482226303019, title = {Bright Beams of Intensity Difference Squeezed Light for use in Sub-shot-noise Imaging}, booktitle = {2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2019}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 05-10, 2019}, publisher = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, organization = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, type = {Proceedings Paper}, abstract = {We present a method for using bright beams of intensity difference squeezed light to perform sub-shot-noise imaging. The intensity correlated twin beams are generated by four wave mixing in rubidium vapour. (C) 2019 The Author(s)}, isbn = {978-1-943580-57-6}, issn = {2160-9020}, author = {Speirs, Rory W. and Brewer, Nicholas R. and Wu, Meng-Chang and Lett, Paul D.} } @article { ISI:000488503500029, title = {Broadband resonator-waveguide coupling for efficient extraction of octave-spanning microcombs}, journal = {Opt. Lett.}, volume = {44}, number = {19}, year = {2019}, month = {OCT 1}, pages = {4737-4740}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {Octave-spanning frequency combs have been successfully demonstrated in Kerr nonlinear microresonators. These microcombs rely on both engineered dispersion, to enable generation of frequency components across the octave, and on engineered coupling, to efficiently extract the generated light into an access waveguide while maintaining a close to critically coupled pump. The latter is challenging, as the spatial overlap between the access waveguide and the ring modes decays with frequency. This leads to strong coupling variation across the octave, with poor extraction at short wavelengths. Here, we investigate how a waveguide wrapped around a portion of the resonator, in a pulley scheme, can improve the extraction of octave-spanning microcombs, in particular at short wavelengths. We use the coupled-mode theory to predict the performance of the pulley couplers and demonstrate good agreement with experimental measurements. Using an optimal pulley coupling design, we demonstrate a 20 dB improvement in extraction at short wavelengths compared to straight waveguide coupling. (C) 2019 Optical Society of America}, issn = {0146-9592}, doi = {10.1364/OL.44.004737}, author = {Moille, Gregory and Li, Qing and Briles, Travis C. and Yu, Su-Peng and Drake, Tara and Lu, Xiyuan and Rao, Ashutosh and Westly, Daron and Papp, Scott B. and Srinivasan, Kartik} } @article { ISI:000504862300005, title = {Coupled electron-impurity and electron-phonon systems as trivial non-Fermi liquids}, journal = {Phys. Rev. B}, volume = {100}, number = {23}, year = {2019}, month = {DEC 30}, pages = {235149}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We consider an electron gas, both in two (2D) and three (3D) dimensions, interacting with quenched impurities and phonons within leading order finite-temperature many-body perturbation theories, calculating the electron self-energies, spectral functions, and momentum distribution functions at finite temperatures. The resultant spectral function is in general highly non-Lorentzian, indicating that the system is not a Fermi liquid in the usual sense. The calculated momentum distribution function cannot be approximated by a Fermi function at any temperature, providing a rather simple example of a non-Fermi liquid with well-understood properties.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.235149}, author = {Buterakos, Donovan and Das Sarma, Sankar} } @article { ISI:000447062400001, title = {Cryogenic trapped-ion system for large scale quantum simulation}, journal = {QUANTUM SCIENCE AND TECHNOLOGY}, volume = {4}, number = {1}, year = {2019}, month = {JAN}, pages = {UNSP 014004}, issn = {2058-9565}, doi = {10.1088/2058-9565/aae0fe}, author = {Pagano, G. and Hess, P. W. and Kaplan, H. B. and Tan, W. L. and Richerme, P. and Becker, P. and Kyprianidis, A. and Zhang, J. and Birckelbaw, E. and Hernandez, M. R. and Wu, Y. and Monroe, C.} } @conference {ISI:000484886200007, title = {Design and performance study of actively holding-off GHz-gated InGaAs/InP SPADs}, booktitle = {ADVANCED PHOTON COUNTING TECHNIQUES XIII}, series = {Proceedings of SPIE}, volume = {10978}, year = {2019}, note = {Conference on Advanced Photon Counting Techniques XIII, Baltimore, MD, APR 17-18, 2019}, pages = {109780C}, publisher = {SPIE}, organization = {SPIE}, type = {Proceedings Paper}, abstract = {High-speed periodic gating of InGaAs/InP single-photon avalanche diodes (SPADs) has allowed these detectors to operate at count rates above 108 per second with low afterpulsing. However, a drawback of high-speed periodic gating is that bias gates are applied continuously, regardless of whether an avalanche has occurred or not. This is disadvantageous because gates immediately following an avalanche have elevated afterpulse probabilities, and the additional charge from these secondary events contributes to the overall afterpulse probability. We investigate this phenomenon in a proof-of-principle experiment in which the series of bias gates is briefly interrupted after an avalanche, and we measure the resulting impact on the afterpulse probability. We observe a significant reduction in afterpulsing when such a bias-gate hold-off is applied to an InGaAs/InP SPAD gated at 1.25 GHz; when one bias gate is omitted after an avalanche the per-gate afterpulse probability is reduced by more than 40 \%. These results indicate that afterpulsing noise at high count rates can be further reduced in high-speed-gated SPADs.}, keywords = {afterpulsing, photon detection, quantum communication, single-photon avalanche diode, Single-photon detector}, isbn = {978-1-5106-2622-5}, issn = {0277-786X}, doi = {10.1117/12.2520620}, author = {Restelli, Alessandro and Bienfang, Joshua C. and Migdall, Alan L.}, editor = {Itzler, MA and Bienfang, JC and McIntosh, KA} } @article {ISI:000461830900002, title = {Development of transmon qubits solely from optical lithography on 300 mm wafers}, journal = {Quantum Sci. Technol.}, volume = {4}, number = {2}, year = {2019}, month = {APR}, pages = {025012}, publisher = {IOP PUBLISHING LTD}, type = {Article}, abstract = {Qubit information processors are increasing in footprint but currently rely on e-beam lithography for patterning the required Josephson junctions (JJs). Advanced optical lithography is an alternative patterning method, and we report on the development of transmon qubits patterned solely with optical lithography. The lithography uses 193 nm wavelength exposure and 300 mm large silicon wafers. Qubits and arrays of evaluation JJs were patterned with process control which resulted in narrow feature distributions: a standard deviation of 0.78\% for a 220 nm linewidth pattern realized across over half the width of the wafers. Room temperature evaluation found a 2.8\%-3.6\% standard deviation in JJ resistance in completed chips. The qubits used aluminum and titanium nitride films on silicon substrates without substantial silicon etching. T-1 times of the qubits were extracted at 26-27 mu s, indicating a low level of material-based qubit defects. This study shows that large wafer optical lithography on silicon is adequate for high-quality transmon qubits, and shows a promising path for improving many-qubit processors.}, keywords = {fabrication, large wafer, QUBIT, silicon, superconducting}, issn = {2058-9565}, doi = {10.1088/2058-9565/ab0ca8}, author = {Foroozani, N. and Hobbs, C. and Hung, C. C. and Olson, S. and Ashworth, D. and Holland, E. and Malloy, M. and Kearney, P. and O{\textquoteright}Brien, B. and Bunday, B. and DiPaola, D. and Advocate, W. and Murray, T. and Hansen, P. and Novak, S. and Bennett, S. and Rodgers, M. and Baker-O{\textquoteright}Neal, B. and Sapp, B. and Barth, E. and Hedrick, J. and Goldblatt, R. and Rao, S. S. Papa and Osborn, K. D.} } @article {ISI:000455814100005, title = {Dynamic polarizability measurements with Lu-176(+)}, journal = {Phys. Rev. A}, volume = {99}, number = {1}, year = {2019}, month = {JAN 15}, pages = {012510}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We measure the differential polarizability of the Lu-176(+) S-1(0) <-> D-3(1) clock transition at multiple wavelengths. This experimentally characterizes the differential dynamic polarizability for frequencies up to 372 THz and allows an experimental determination of the dynamic correction to the blackbody radiation shift for the clock transition. In addition, measurements at the near resonant wavelengths of 598 and 646 nm determine the two dominant contributions to the differential dynamic polarizability below 372 THz. These additional measurements are carried out by two independent methods to verify the validity of our methodology. We also carry out a theoretical calculation of the polarizabilities using the hybrid method that combines the configuration interaction (CI) and the coupled-cluster approaches, incorporating for the first time quadratic nonlinear terms and partial triple excitations in the coupled-cluster calculations. The experimental measurements of the vertical bar < D-3(1)parallel to r parallel to P-3(J)>vertical bar matrix elements provide high-precision benchmarks for this theoretical approach.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.99.012510}, author = {Arnold, K. J. and Kaewuam, R. and Tan, T. R. and Porsev, S. G. and Safronova, M. S. and Barrett, M. D.} } @article {ISI:000482136700013, title = {Dynamic suppression of Rayleigh backscattering in dielectric resonators}, journal = {Optica}, volume = {6}, number = {8}, year = {2019}, month = {AUG 20}, pages = {1016-1022}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {The ultimate limits of performance for any classical optical system are set by sub-wavelength fluctuations within the host material, which may be frozen-in or even dynamically induced. The most common manifestation of such subwavelength disorder is Rayleigh light scattering, which is observed in nearly all waveguiding technologies today and can lead to both irreversible radiative losses as well as undesirable intermodal coupling, While it has been shown that backscattering from disorder can be suppressed by breaking the time-reversal symmetry in magneto-optic and topological insulator materials, common optical dielectrics possess neither of these properties. Here, we demonstrate an optomechanical approach for dynamically suppressing Rayleigh backscattering within dielectric resonators. We achieve this by locally breaking the time-reversal symmetry in a silica resonator through a Brillouin scattering interaction that is available in all materials. Near-complete suppression of Rayleigh backscattering is experimentally confirmed through two independent measurements-the elimination of a commonly seen normal-mode splitting or {\textquoteleft}{\textquoteleft}doublet{{\textquoteright}{\textquoteright}} effect and by measurement of the reduction in intrinsic optical loss. Additionally, a reduction of the back-reflections caused by disorder is also observed. Our results provide new evidence that it is possible to dynamically suppress Rayleigh backscattering within any optical dielectric medium using time-reversal symmetry breaking, for achieving robust light propagation in spite of scatterers or defects. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {2334-2536}, doi = {10.1364/OPTICA.6.001016}, author = {Kim, Seunghwi and Taylor, Jacob M. and Bahl, Gaurav} } @article {ISI:000483304200006, title = {Efficient telecom-to-visible spectral translation through ultralow power nonlinear nanophotonics}, journal = {Nat. Photonics}, volume = {13}, number = {9}, year = {2019}, month = {SEP}, pages = {593+}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {The ability to spectrally translate lightwave signals in a compact, low-power platform is at the heart of the promise of nonlinear nanophotonic technologies. For example, a device to connect the telecommunications band with visible and short near-infrared wavelengths can enable a connection between high-performance chip-integrated lasers based on scalable nanofabrication technology with atomic systems used for time and frequency metrology. Although second-order nonlinear (chi((2))) systems are the natural approach for bridging such large spectral gaps, here we show that third-order nonlinear (chi((3))) systems, despite their typically much weaker nonlinear response, can realize spectral translation with unprecedented performance. By combining resonant enhancement with nanophotonic mode engineering in a silicon nitride microring resonator, we demonstrate efficient spectral translation of a continuous-wave signal from the telecom band (similar to 1,550 nm) to the visible band (similar to 650 nm) through cavity-enhanced four-wave mixing. We achieve such translation over a wide spectral range >250 THz with a translation efficiency of (30.1 +/- 2.8)\% and using an ultralow pump power of (329 +/- 13) mu W. The translation efficiency projects to (274 +/- 28)\% at 1 mW and is more than an order of magnitude larger than what has been achieved in current nanophotonic devices.}, issn = {1749-4885}, doi = {10.1038/s41566-019-0464-9}, author = {Lu, Xiyuan and Moille, Gregory and Li, Qing and Westlyl, Daron A. and Singh, Anshuman and Rao, Ashutosh and Yu, Su-Peng and Briles, Travis C. and Papp, Scott B. and Srinivasan, Kartik} } @article {ISI:000466237600004, title = {Elastic rate coefficients for Li+H-2 collisions in the calibration of a cold-atom vacuum standard}, journal = {Phys. Rev. A}, volume = {99}, number = {4}, year = {2019}, month = {APR 29}, pages = {042704}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Ongoing efforts at the National Institute of Standards and Technology in creating a cold-atom vacuum standard device have prompted theoretical investigations of atom-molecule collision processes that characterize its operation. Such a device will operate as a primary standard for the ultrahigh-vacuum and extreme-high-vacuum regimes. This device operates by relating loss of ultracold lithium atoms from a conservative trap by collisions with ambient atoms and molecules to the background density and thus pressure through the ideal gas law. The predominant background constituent in these environments is molecular hydrogen H-2. We compute the relevant Li+H-2 Born-Oppenheimer potential energy surface, paying special attention to its uncertainty. Coupled-channel calculations are then used to obtain total rate coefficients, which include momentum-changing elastic and inelastic processes. We find that inelastic rotational quenching of H-2 is negligible near room temperature. For a (T = 300)-K gas of H-2 and 1.0-mu K gas of Li atoms prepared in a single hyperfine state, the total rate coefficients are 6.0(1) x 10(-9) cm(3)/s for both Li-6 and Li-7 isotopes, where the number in parentheses corresponds to a one-standard-deviation combined statistical and systematic uncertainty. We find that a 10-K increase in the H-2 temperature leads to a 1.9\% increase in the rate coefficients for both isotopes. For Li temperatures up to 100 mu K, changes are negligible. Finally, a semiclassical Born approximation significantly overestimates the rate coefficients. The difference is at least ten times the uncertainty of the coupled-channel result.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.99.042704}, author = {Makrides, Constantinos and Barker, Daniel S. and Fedchak, James A. and Scherschligt, Julia and Eckel, Stephen and Tiesinga, Eite} } @article {ISI:000473271300044, title = {Evolution of large-scale flow from turbulence in a two-dimensional superfluid}, journal = {Science}, volume = {364}, number = {6447}, year = {2019}, month = {JUN 28}, pages = {1267+}, publisher = {AMER ASSOC ADVANCEMENT SCIENCE}, type = {Article}, abstract = {Nonequilibrium interacting systems can evolve to exhibit large-scale structure and order. In two-dimensional turbulent flow, the seemingly random swirling motion of a fluid can evolve toward persistent large-scale vortices. To explain such behavior, Lars Onsager proposed a statistical hydrodynamic model based on quantized vortices. Here, we report on the experimental confirmation of Onsager{\textquoteright}s model. We dragged a grid barrier through an oblate superfluid Bose-Einstein condensate to generate nonequilibrium distributions of vortices. We observed signatures of an inverse energy cascade driven by the evaporative heating of vortices, leading to steady-state configurations characterized by negative absolute temperatures. Our results open a pathway for quantitative studies of emergent structures in interacting quantum systems driven far from equilibrium.}, issn = {0036-8075}, doi = {10.1126/science.aat5793}, author = {Johnstone, Shaun P. and Groszek, Andrew J. and Starkey, Philip T. and Billington, Christopher J. and Simula, Tapio P. and Helmerson, Kristian} } @article { ISI:000504435500005, title = {Ferromagnetism in quantum dot plaquettes}, journal = {Phys. Rev. B}, volume = {100}, number = {22}, year = {2019}, month = {DEC 23}, pages = {224421}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Following recent experimental progress concerning Nagaoka ferromagnetism in finite-size quantum dot plaquettes, a general theoretical analysis is warranted in order to ascertain in rather generic terms which arrangements of a small number of quantum dots can produce saturated ferromagnetic ground states and under which constraints on interaction and interdot tunneling in the plaquette. This is particularly necessary since Nagaoka ferromagnetism is fragile and arises only under rather special conditions. We test the robustness of ground state ferromagnetism in the presence of a long-range Coulomb interaction and long-range as well as short-range interdot hopping by modeling a wide range of different plaquette geometries accessible by arranging a few (similar to 4) quantum dots in a controlled manner. We find that ferromagnetism is robust to the presence of long-range Coulomb interactions, and we develop conditions constraining the tunneling strength such that the ground state is ferromagnetic. Additionally, we predict the presence of a partially spin-polarized ferromagnetic state for 4 electrons in a Y-shaped 4-quantum-dot plaquette. Finally, we consider 4 electrons in a ring of 5 dots. This does not satisfy the Nagaoka condition; however, we show that the ground state is spin 1 for strong, but not infinite, on-site interaction. Thus, even though Nagaoka{\textquoteright}s theorem does not apply, the ground state for the finite system with one hole in a ring of 5 dots is partially ferromagnetic. We provide detailed fully analytical results for the existence or not of ferromagnetic ground states in several quantum dot geometries which can be studied in currently available coupled quantum dot systems.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.224421}, author = {Buterakos, Donovan and Das Sarma, Sankar} } @article {ISI:000466889100001, title = {A fiber-integrated nanobeam single photon source emitting at telecom wavelengths}, journal = {Appl. Phys. Lett.}, volume = {114}, number = {17}, year = {2019}, month = {APR 29}, pages = {171101}, publisher = {AMER INST PHYSICS}, type = {Article}, abstract = {Fiber-coupled single photon sources are considered important components of photonics-based quantum information processors. Most fibercoupled single photon sources require careful alignment between fibers and quantum emitters. In this work, we present an alignment-free fiber-integrated single photon source based on an InAs/InP quantum dot emitting at telecom wavelengths. We designed a nanobeam containing the quantum dots attached to a fiber taper. The adiabatic tapered coupler of the nanobeam enables efficient light coupling to the fiber taper. Using a tungsten probe in a focused ion beam system, we transferred the nanobeam to the fiber taper. The observed fiber-coupled single photon emission occurs with a brightness of 1.4\% and a purity of 83\%. This device provides a building block for fiber-optic quantum circuits that have various applications, such as quantum communication and distributed quantum computing. Published under license by AIP Publishing.}, issn = {0003-6951}, doi = {10.1063/1.5089907}, author = {Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Aghaeimeibodi, Shahriar and Karasahin, Aziz and Richardson, Christopher J. K. and Waks, Edo} } @article {ISI:000482940400006, title = {Frequency shifts due to Stark effects on a rubidium two-photon transition}, journal = {Phys. Rev. A}, volume = {100}, number = {2}, year = {2019}, month = {AUG 28}, pages = {023417}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The 5S(1/2) -> 5D(5/2) two-photon transition in Rb is of interest for the development of a compact optical atomic clock. Here we present a rigorous calculation of the 778.1-nm ac Stark shift {[}2.30(4) x 10(-13)(mW/mm(2))(-1)] that is in good agreement with our measured value of 2.5(2) x 10(-13)(mW/mm(2))(-1). We include a calculation of the temperature-dependent blackbody radiation (BBR) shift, and we predict that the clock could be operated either with zero net BBR shift {[}T = 495.9(27) K] or with zero first-order sensitivity {[}T = 368.1(14) K]. Also described is the calculation of the dc Stark shift of 5.5(1) x 10(-15)/(V/cm(2)) as well as clock sensitivities to optical alignment variations in both a cat{\textquoteright}s eye and a flat mirror retroreflector. Finally, we characterize these Stark effects, discussing mitigation techniques necessary to reduce final clock instabilities.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.023417}, author = {Martin, Kyle W. and Stuhl, Benjamin and Eugenio, Jon and Safronova, Marianna S. and Phelps, Gretchen and Burke, John H. and Lemke, Nathan D.} } @article {ISI:000452005100052, title = {Gateless and reversible Carrier density tunability in epitaxial graphene devices functionalized with chromium tricarbonyl}, journal = {Carbon}, volume = {142}, year = {2019}, month = {FEB}, pages = {468-474}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, abstract = {Monolayer epitaxial graphene (EG) has been shown to have clearly superior properties for the development of quantized Hall resistance (QHR) standards. One major difficulty with QHR devices based on EG is that their electrical properties drift slowly over time if the device is stored in air due to adsorption of atmospheric molecular dopants. The crucial parameter for device stability is the charge carrier density, which helps determine the magnetic flux density required for precise QHR measurements. This work presents one solution to this problem of instability in air by functionalizing the surface of EG devices with chromium tricarbonyl - Cr(CO)(3). Observations of carrier density stability in air over the course of one year are reported, as well as the ability to tune the carrier density by annealing the devices. For low temperature annealing, the presence of Cr(CO)(3) stabilizes the electrical properties and allows for the reversible tuning of the carrier density in millimeter-scale graphene devices close to the Dirac point. Precision measurements in the quantum Hall regime show no detrimental effect on the carrier mobility. Published by Elsevier Ltd.}, issn = {0008-6223}, doi = {10.1016/j.carbon.2018.10.085}, author = {Rigosi, Albert F. and Kruskopf, Mattias and Hill, Heather M. and Jin, Hanbyul and Wu, Bi-Yi and Johnson, Philip E. and Zhang, Siyuan and Berilla, Michael and Walker, Angela R. Hight and Hacker, Christina A. and Newell, David B. and Elmquist, Randolph E.} } @article { ISI:000493516700001, title = {Gauging fractons: Immobile non-Abelian quasiparticles, fractals, and position-dependent degeneracies}, journal = {Phys. Rev. B}, volume = {100}, number = {15}, year = {2019}, month = {OCT 29}, pages = {155146}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The study of gapped quantum many-body systems in three spatial dimensions has uncovered the existence of quantum states hosting quasiparticles that are confined, not by energetics but by the structure of local operators, to move along lower dimensional submanifolds. These so-called {\textquoteleft}{\textquoteleft}fracton{{\textquoteright}{\textquoteright}} phases are beyond the usual topological quantum field theory description, and thus require new theoretical frameworks to describe them. Here we consider coupling fracton models to topological quantum field theories in (3 + 1) dimensions by starting with two copies of a known fracton model and gauging the Z(2) symmetry that exchanges the two copies. This yields a class of exactly solvable lattice models that we study in detail for the case of the X-cube model and Haah{\textquoteright}s cubic code. The resulting phases host finite-energy non-Abelian immobile quasiparticles with robust degeneracies that depend on their relative positions. The phases also host non-Abelian string excitations with robust degeneracies that depend on the string geometry. Applying the construction to Haah{\textquoteright}s cubic code in particular provides an exactly solvable model with finite energy yet immobile non-Abelian quasiparticles that can only be created at the corners of operators with fractal support.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.155146}, author = {Bulmash, Daniel and Barkeshli, Maissam} } @article {ISI:000483803100006, title = {Ground state of the three-dimensional BCS d-wave superconductor}, journal = {Phys. Rev. B}, volume = {100}, number = {10}, year = {2019}, month = {SEP 4}, pages = {104503}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We determine the mean-field ground state of the three-dimensional rotationally symmetric d-wave (l = 2) superconductor at weak coupling. It is a noninert state, invariant under the symmetry C-2 only, which breaks time-reversal symmetry almost maximally, and features a high but again less-than-maximal average magnetization. The state obtained by minimization of the expanded sixth-order Ginzburg-Landau free energy is found to be an excellent approximation to the true ground state. The coupling to a parasitic s-wave component has only a minuscule quantitative and no qualitative effect on the ground state.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.104503}, author = {Herbut, Igor F. and Boettcher, Igor and Mandal, Subrata} } @article {ISI:000459579600002, title = {Incorporation of random alloy GaBixAs1-x barriers in InAs quantum dot molecules: Energy levels and confined hole states}, journal = {Phys. Rev. B}, volume = {99}, number = {7}, year = {2019}, month = {FEB 22}, pages = {075308}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Self-assembled InAs quantum dots (QDs), which have long hole-spin coherence times and are amenable to optical control schemes, have long been explored as building blocks for qubit architectures. One such design consists of vertically stacking two QDs to create a QD molecule (QDM) and using the spin-mixing properties of {\textquoteleft}{\textquoteleft}moleculelike{{\textquoteright}{\textquoteright}} coupled hole states for all-optical qubit manipulation. In this paper, the first of two papers, we introduce the incorporation of dilute GaBixAs1-x alloys in the barrier region between the two dots. GaBixAs1-x is expected to increase the spin mixing of the molecular states needed for qubit operations by raising the barrier valence-band edge and spin-orbit splitting. Using an atomistic tight-binding model, we compute the properties of GaBixAs1-x and the modification of hole states that arise when the alloy is used in the barrier of an InAs QDM. An atomistic treatment is necessary to correctly capture nontraditional alloy effects such as the band-anticrossing valence band. It also allows for the study of configurational variances and clustering effects of the alloy. We find that in InAs QDMs with a GaBiAs interdot barrier, electron states are not strongly affected by the inclusion of Bi. However, hole states are much more sensitive to the presence and configuration of Bi in the barriers. By independently studying the alloy-induced strain and electronic scattering off Bi and As orbitals, we conclude that an initial increase in QDM hole-state energy at low Bi concentration is caused by the alloy-induced strain. We further find that the decrease in QDM hole energy at higher Bi concentrations can only be explained when both alloy strain and orbital effects are considered. In our second paper, we use the understanding developed here to discuss how the alloyed barriers contribute to enhancement in hole spin-mixing and the implications for QDM qubit architectures.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.075308}, author = {Lin, Arthur and Doty, Matthew F. and Bryant, Garnett W.} } @conference {ISI:000482226301193, title = {Integration of Quantum Emitters with Lithium Niobate Photonics}, booktitle = {2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2019}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 05-10, 2019}, publisher = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, organization = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, type = {Proceedings Paper}, abstract = {We demonstrate integration of telecom quantum dots with lithium niobate photonics using a pick-and-place technique. Second order photon correlation measurement performed with an on-chip beamsplitter confirms the single-photon nature of the emission. (C) 2019 The Author(s)}, isbn = {978-1-943580-57-6}, issn = {2160-9020}, author = {Aghaeimeibodi, Shahriar and Desiatov, Boris and Kim, Je-Hyung and Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Karasahin, Aziz and Richardson, Christopher J. K. and Leavitt, Richard P. and Loncar, Marko and Waks, Edo} } @article { ISI:000459554300005, title = {Large stark tuning of InAs/InP quantum dots}, journal = {APPLIED PHYSICS LETTERS}, volume = {114}, number = {7}, year = {2019}, month = {FEB 18}, pages = {071105}, issn = {0003-6951}, doi = {10.1063/1.5082560}, author = {Aghaeimeibodi, Shahriar and Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Richardson, Christopher J. K. and Waks, Edo} } @article {ISI:000483578600012, title = {Measurements of the branching ratios for 6P(1/2) decays in Ba-138(+)}, journal = {Phys. Rev. A}, volume = {100}, number = {3}, year = {2019}, month = {SEP 3}, pages = {032503}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Measurement of the branching ratios for 6P(1/2) decays to 6S(1/2) and 5D(3/2) in Ba-138(+) are reported with the decay probability from 6P(1/2) to 5D(3/2) measured to be p = 0.268177 +/- (37)(stat)-(20)(sys). This result differs from a recent report by 12 sigma. A detailed account of systematics is given, and the likely source of the discrepancy is identified. The new value of the branching reported here is combined with previous experimental results to give a new estimate of tau = 7.855(10) ns for the 6P(1/2) lifetime. In addition, ratios of matrix elements calculated from theory are combined with experimental results to provide improved theoretical estimates of the 6P(3/2) lifetime and the associated matrix elements.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.032503}, author = {Arnold, K. J. and Chanu, S. R. and Kaewuam, R. and Tan, T. R. and Yeo, L. and Zhang, Zhiqiang and Safronova, M. S. and Barrett, M. D.} } @article { ISI:000504926700014, title = {Milliwatt-threshold visible-telecom optical parametric oscillation using silicon nanophotonics}, journal = {Optica}, volume = {6}, number = {12}, year = {2019}, month = {DEC 20}, pages = {1535-1541}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {The on-chip creation of coherent light at visible wavelengths is crucial to field-level deployment of spectroscopy and metrology systems. Although on-chip lasers have been implemented in specific cases, a general solution that is not restricted by limitations of specific gain media has not been reported, to the best of our knowledge. Here, we propose creating visible light from an infrared pump by widely separated optical parametric oscillation (OPO) using silicon nanophotonics. The OPO creates signal and idler light in the 700 nm and 1300 nm bands, respectively, with a 900 nm pump. It operates at a threshold power of (0.9 +/- 0.1) mW, over 50 x smaller than other widely separated microcavity OPO works, which have been reported only in the infrared. This low threshold enables direct pumping without need of an intermediate optical amplifier. We further show how the device design can be modified to generate 780 nm and 1500 nm light with a similar power efficiency. Our nanophotonic OPO shows distinct advantages in power efficiency, operation stability, and device scalability, and is a major advance towards flexible on-chip generation of coherent visible light.}, issn = {2334-2536}, doi = {10.1364/OPTICA.6.001535}, author = {Lu, Xiyuan and Moille, Gregory and Singh, Anshuman and Li, Qing and Westly, Daron A. and Rao, Ashutosh and Yu, Su-Peng and Briles, Travis C. and Papp, Scott B. and Srinivasan, Kartik} } @article { ISI:000498063400002, title = {Nondestructive Cooling of an Atomic Quantum Register via State-Insensitive Rydberg Interactions}, journal = {Phys. Rev. Lett.}, volume = {123}, number = {21}, year = {2019}, month = {NOV 20}, pages = {213603}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We propose a protocol for sympathetically cooling neutral atoms without destroying the quantum information stored in their internal states. This is achieved by designing state-insensitive Rydberg interactions between the data-carrying atoms and cold auxiliary atoms. The resulting interactions give rise to an effective phonon coupling, which leads to the transfer of heat from the data atoms to the auxiliary atoms, where the latter can be cooled by conventional methods. This can be used to extend the lifetime of quantum storage based on neutral atoms and can have applications for long quantum computations. The protocol can also be modified to realize state-insensitive interactions between the data and the auxiliary atoms but tunable and nontrivial interactions among the data atoms, allowing one to simultaneously cool and simulate a quantum spin model.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.123.213603}, author = {Belyansky, Ron and Young, Jeremy T. and Bienias, Przemyslaw and Eldredge, Zachary and Kaufman, Adam M. and Zoller, Peter and Gorshkov, V, Alexey} } @article {ISI:000455320600043, title = {Observation of chiral zero mode in inhomogeneous three-dimensional Weyl metamaterials}, journal = {Science}, volume = {363}, number = {6423}, year = {2019}, month = {JAN 11}, pages = {148-151}, publisher = {AMER ASSOC ADVANCEMENT SCIENCE}, type = {Article}, abstract = {Owing to the chirality of Weyl nodes, the Weyl systems can support one-way chiral zero modes under a strong magnetic field, which leads to nonconservation of chiral currents-the so-called chiral anomaly. Although promising for robust transport of optical information, the zero chiral bulk modes have not been observed in photonics. Here we design an inhomogeneous Weyl metamaterial in which a gauge field is generated for the Weyl nodes by engineering the individual unit cells. We experimentally confirm the presence of the gauge field and observe the zero-order chiral Landau level with one-way propagation. Without breaking the time-reversal symmetry, our system provides a route for designing an artificial magnetic field in three-dimensional photonic Weyl systems and may have potential for device applications in photonics.}, issn = {0036-8075}, doi = {10.1126/science.aau7707}, author = {Jia, Hongwei and Zhang, Ruixing and Gao, Wenlong and Guo, Qinghua and Yang, Biao and Hu, Jing and Bi, Yangang and Xiang, Yuanjiang and Liu, Chaoxing and Zhang, Shuang} } @article {ISI:000467042000002, title = {Observation of Many-Body Localization in a One-Dimensional System with a Single-Particle Mobility Edge}, journal = {Phys. Rev. Lett.}, volume = {122}, number = {17}, year = {2019}, month = {MAY 3}, pages = {170403}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We experimentally study many-body localization (MBL) with ultracold atoms in a weak onedimensional quasiperiodic potential, which in the noninteracting limit exhibits an intermediate phase that is characterized by a mobility edge. We measure the time evolution of an initial charge density wave after a quench and analyze the corresponding relaxation exponents. We find clear signatures of MBL when the corresponding noninteracting model is deep in the localized phase. We also critically compare and contrast our results with those from a tight-binding Aubry-Andre model, which does not exhibit a singleparticle intermediate phase, in order to identify signatures of a potential many-body intermediate phase.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.122.170403}, author = {Kohlert, Thomas and Scherg, Sebastian and Li, Xiao and Lueschen, Henrik P. and S. Das Sarma and Bloch, Immanuel and Aidelsburger, Monika} } @article {ISI:000462898900011, title = {Optical response of Luttinger semimetals in the normal and superconducting states}, journal = {Phys. Rev. B}, volume = {99}, number = {12}, year = {2019}, month = {MAR 25}, pages = {125146}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We investigate the optical response properties of three-dimensional Luttinger semimetals with the Fermi energy close to a quadratic band touching point. In particular, in order to address recent experiments on the spectroscopy of pyrochlore iridates and half-Heusler superconductors, we derive expressions for the optical conductivity in both the normal and general superconducting states in the linear response regime within the random phase approximation. The response functions can be decomposed into contributions from intraband and interband transitions, the latter comprising a genuine signature of the quadratic band touching point. We demonstrate the importance of interband transitions in the optical response in the normal state both in the homogeneous and quasistatic limit. Our analysis reveals a factorization property of the homogeneous conductivity in the spatially anisotropic case and the divergence of the conductivity for strong spatial anisotropy. In the quasistatic limit, the response is dominated by interband transitions and significantly different from systems with a single parabolic band. As an applications of the formalism in the superconducting state we compute the optical conductivity and superfluid density for the s-wave singlet superconducting case for both finite and vanishing chemical potential.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.125146}, author = {Boettcher, Igor} } @article {ISI:000473132200039, title = {Orbital-flop Induced Magnetoresistance Anisotropy in Rare Earth Monopnictide CeSb}, journal = {Nat. Commun.}, volume = {10}, year = {2019}, month = {JUN 28}, pages = {2875}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {The charge and spin of the electrons in solids have been extensively exploited in electronic devices and in the development of spintronics. Another attribute of electrons-their orbital nature-is attracting growing interest for understanding exotic phenomena and in creating the next-generation of quantum devices such as orbital qubits. Here, we report on orbital-flop induced magnetoresistance anisotropy in CeSb. In the low temperature high magnetic-field driven ferromagnetic state, a series of additional minima appear in the angle-dependent magnetoresistance. These minima arise from the anisotropic magnetization originating from orbital-flops and from the enhanced electron scattering from magnetic multidomains formed around the first-order orbital-flop transition. The measured magnetization anisotropy can be accounted for with a phenomenological model involving orbital-flops and a spin-valve-like structure is used to demonstrate the viable utilization of orbital-flop phenomenon. Our results showcase a contribution of orbital behavior in the emergence of intriguing phenomena.}, issn = {2041-1723}, doi = {10.1038/s41467-019-10624-z}, author = {Xu, Jing and Wu, Fengcheng and Bao, Jin-Ke and Han, Fei and Xiao, Zhi-Li and Martin, Ivar and Lyu, Yang-Yang and Wang, Yong-Lei and Chung, Duck Young and Li, Mingda and Zhang, Wei and Pearson, John E. and Jiang, Jidong S. and Kanatzidis, Mercouri G. and Kwok, Wai-Kwong} } @article {14286, title = {Parametric Heating in a 2D Periodically Driven Bosonic System: Beyond the Weakly Interacting Regime}, journal = {Physical Review X}, volume = {9}, year = {2019}, pages = {011047}, author = {Boulier, T and Maslek, J and Bukov, M and Bracamontes, C and Magnan, E and Lellouch, S and Demler, E and Goldman, N and Porto, J V} } @article {ISI:000461066200001, title = {Parametric Heating in a 2D Periodically Driven Bosonic System: Beyond the Weakly Interacting Regime}, journal = {Phys. Rev. X}, volume = {9}, number = {1}, year = {2019}, month = {MAR 13}, pages = {011047}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We experimentally investigate the effects of parametric instabilities on the short-time heating process of periodically driven bosons in 2D optical lattices with a continuous transverse (tube) degree of freedom. We analyze three types of periodic drives: (i) linear along the x-lattice direction only, (ii) linear along the lattice diagonal, and (iii) circular in the lattice plane. In all cases, we demonstrate that the Bose-Einstein condensate (BEC) decay is dominated by the emergence of unstable Bogoliubov modes, rather than scattering in higher Floquet bands, in agreement with recent theoretical predictions. The observed BEC depletion rates are much higher when shaking along both the x and y directions, as opposed to only x or only y. We also report an explosion of the decay rates at large drive amplitudes and suggest a phenomenological description beyond the Bogoliubov theory. In this strongly coupled regime, circular drives heat faster than diagonal drives, which illustrates the nontrivial dependence of the heating on the choice of drive.}, issn = {2160-3308}, doi = {10.1103/PhysRevX.9.011047}, author = {Boulier, T. and Maslek, J. and Bukov, M. and Bracamontes, C. and Magnan, E. and Lellouch, S. and Demler, E. and Goldman, N. and Porto, V, J.} } @article {ISI:000473018000001, title = {Parton construction of particle-hole-conjugate Read-Rezayi parafermion fractional quantum Hall states and beyond}, journal = {Phys. Rev. B}, volume = {99}, number = {24}, year = {2019}, month = {JUN 19}, pages = {241108}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The Read-Rezayi (RR) parafermion states form a series of exotic non-Abelian fractional quantum Hall (FQH) states at filling. = k/(k + 2). Computationally, the wave functions of these states are prohibitively expensive to generate for large systems. We introduce a series of parton states, denoted (\$2) over bar (k)1(k+1), and show that they lie in the same universality classes as the particle-hole-conjugate RR ({{\textquoteright}{\textquoteright}}anti-RR{{\textquoteright}{\textquoteright}}) states. Our analytical results imply that a {[}U(1)(k+1) xU(2k)(-1)]/{[}SU(k)(-2) xU(1)(-1)] coset conformal field theory describes the edge excitations of the (2) over bar (k)1(k+1) state, suggesting nontrivial dualities with respect to previously known descriptions. The parton construction allows wave functions in anti-RR phases to be generated for hundreds of particles. We further propose the parton sequence (n) over bar(2) over bar (4), with n = 1, 2, 3, to describe the FQH states observed at nu= 2 + 1/2, 2 + 2/5, and 2 + 3/8.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.241108}, author = {Balram, Ajit C. and Barkeshli, Maissam and Rudner, Mark S.} } @article {14481, title = {Perfect Andreev reflection due to the Klein paradox in a topological superconducting state}, journal = {Nature}, volume = {570}, year = {2019}, pages = {344{\textendash}348}, abstract = {In 1928, Dirac proposed a wave equation to describe relativistic electrons1. Shortly afterwards, Klein solved a simple potential step problem for the Dirac equation and encountered an apparent paradox: the potential barrier becomes transparent when its height is larger than the electron energy. For massless particles, backscattering is completely forbidden in Klein tunnelling, leading to perfect transmission through any potential barrier2,3. The recent advent of condensed-matter systems with Dirac-like excitations, such as graphene and topological insulators, has opened up the possibility of observing Klein tunnelling experimentally4{\textendash}6. In the surface states of topological insulators, fermions are bound by spin{\textendash}momentum locking and are thus immune from backscattering, which is prohibited by time-reversal symmetry. Here we report the observation of perfect Andreev reflection in point-contact spectroscopy{\textendash}-a clear signature of Klein tunnelling and a manifestation of the underlying {\textquoteleft}relativistic{\textquoteright}physics of a proximity-induced superconducting state in a topological Kondo insulator. Our findings shed light on a previously overlooked aspect of topological superconductivity and can serve as the basis for a unique family of spintronic and superconducting devices, the interface transport phenomena of which are completely governed by their helical topological states.

}, isbn = {1476-4687}, doi = {10.1038/s41586-019-1305-1}, url = {https://doi.org/10.1038/s41586-019-1305-1}, author = {Lee, Seunghun and Stanev, Valentin and Zhang, Xiaohang and Stasak, Drew and Flowers, Jack and Higgins, Joshua S. and Dai, Sheng and Blum, Thomas and Pan, Xiaoqing and Yakovenko, Victor M. and Paglione, Johnpierre and Greene, Richard L. and Galitski, Victor and Takeuchi, Ichiro} } @article { ISI:000492332900006, title = {Polarizability assessments of ion-based optical clocks}, journal = {Phys. Rev. A}, volume = {100}, number = {4}, year = {2019}, month = {OCT 24}, pages = {043418}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {It is shown that the dynamic differential scalar polarizability of the S-1/2 - D-5/2 transition in Ba-138(+) can be determined to an inaccuracy below 0.5\% across a wide wavelength range (lambda > 700 nm). This can be achieved using measurements for which accurate determination of laser intensity is not required, and most of the required measurements are already in the literature. Measurement of a laser-induced ac-Stark shift of the clock transition would then provide an in situ measurement of the laser{\textquoteright}s intensity to the same 0.5\% level of inaccuracy, which is not easily achieved by other means. This would allow accurate polarizability measurements for clock transitions in other ions, through comparison with Ba-138(+). The approach would be equally applicable to Sr+ and Ca+, with the latter being immediately applicable to Al+/Ca+ quantum logic clocks.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.043418}, author = {Barrett, M. D. and Arnold, K. J. and Safronova, M. S.} } @article { ISI:000488249400003, title = {Polynomial time algorithms for estimating spectra of adiabatic Hamiltonians}, journal = {Phys. Rev. A}, volume = {100}, number = {3}, year = {2019}, month = {SEP 30}, pages = {032336}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Much research regarding quantum adiabatic optimization has focused on stoquastic Hamiltonians with Hamming-symmetric potentials, such as the well-studied {\textquoteleft}{\textquoteleft}spike{{\textquoteright}{\textquoteright}} example. Due to the large amount of symmetry in these potentials such problems are readily open to analysis both analytically and computationally. However, more realistic potentials do not have such a high degree of symmetry and may have many local minima Here we present a somewhat more realistic class of problems consisting of many individually Hamming-symmetric potential wells. For two or three such wells we demonstrate that such a problem can be solved exactly in time polynomial in the number of qubits and wells. For greater than three wells, we present a tight-binding approach with which to efficiently analyze the performance of such Hamiltonians in an adiabatic computation. We provide several basic examples designed to highlight the usefulness of this toy model and to give insight into using the tight-binding approach to examining it, including (1) an adiabatic unstructured search with a transverse field driver and a prior guess to the marked item and (2) a scheme for adiabatically simulating the ground states of small collections of strongly interacting spins, with an explicit demonstration for an Ising-model Hamiltonian.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.032336}, author = {Bringewatt, Jacob and Dorland, William and Jordan, Stephen P.} } @conference {ISI:000481657400006, title = {A post-processing-free single-photon random number generator with ultra-low latency}, booktitle = {ADVANCES IN PHOTONICS OF QUANTUM COMPUTING, MEMORY, AND COMMUNICATION XII}, series = {Proceedings of SPIE}, volume = {10933}, year = {2019}, note = {Conference on Advances in Photonics of Quantum Computing, Memory, and Communication XII, San Francisco, CA, FEB 05-07, 2019}, pages = {109330F}, publisher = {SPIE}, organization = {SPIE}, type = {Proceedings Paper}, abstract = {The low-latency requirements of a loophole-free Bell test prohibit time-consuming post-processing steps that arc often used to improve the statistical quality of a physical random number generator (RNG). Here we demonstrate a post-processing-free RNG that produces a random bit within 2.4(2) ns of an input trigger. We use the Allan variance as a tool for characterizing non-idealities in the RNG and designing a feedback mechanism to account for and correct long-term drift. The impact of the feedback on the predictability of the output is less than 6.4 x 10(7), and results in a system capable of 24 hour operation with output that is statistically indistinguishable from a balanced Bernoulli process.}, keywords = {Bell test, low latency, Quantum Information, random number generator, single-photon}, isbn = {978-1-5106-2509-9}, issn = {0277-786X}, doi = {10.1117/12.2514855}, author = {Wayne, Michael A. and Migdall, Alan L. and Levine, Zachary H. and Bienfang, Joshua C.}, editor = {Hemmer, PR and Migdall, AL and UlHasan, Z} } @article {ISI:000473540500004, title = {Prediction of a Non-Abelian Fractional Quantum Hall State with f-Wave Pairing of Composite Fermions in Wide Quantum Wells}, journal = {Phys. Rev. Lett.}, volume = {123}, number = {1}, year = {2019}, month = {JUL 2}, pages = {016802}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We theoretically investigate the nature of the state at the quarter filled lowest Landau level and predict that, as the quantum well width is increased, a transition occurs from the composite fermion Fermi sea into a novel non-Abelian fractional quantum Hall state that is topologically equivalent to f-wave pairing of composite fermions. This state is topologically distinct from the familiar p-wave paired Pfaffian state. We compare our calculated phase diagram with experiments and make predictions for many observable quantities.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.123.016802}, author = {Faugno, W. N. and Balram, Ajit C. and Barkeshli, Maissam and Jain, J. K.} } @conference {ISI:000482226301355, title = {Quantum-correlated Light Source from Dual-seeded Four-wave Mixing with a Diode Laser System}, booktitle = {2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2019}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 05-10, 2019}, publisher = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, organization = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, type = {Proceedings Paper}, abstract = {We have obtained broadband intensity-difference squeezing from sub 10 Hz to 20 MHz via four-wave mixing (4WM) in a rubidium vapor. This was accomplished by dual-seeding the 4WM process and using semiconductor diode lasers. (C) 2019 The Author(s)}, isbn = {978-1-943580-57-6}, issn = {2160-9020}, author = {Wu, Meng-Chang and Brewer, Nicholas R. and Speirs, Rory W. and Schmittberger, Bonnie L. and Jones, Kevin M. and Lett, Paul D.} } @article {ISI:000462935500003, title = {Scale-Invariant Continuous Entanglement Renormalization of a Chern Insulator}, journal = {Phys. Rev. Lett.}, volume = {122}, number = {12}, year = {2019}, month = {MAR 27}, pages = {120502}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The multiscale entanglement renormalization ansatz (MERA) postulates the existence of quantum circuits that renormalize entanglement in real space at different length scales. Chem insulators, however, cannot have scale-invariant discrete MERA circuits with a finite bond dimension. In this Letter, we show that the continuous MERA (cMERA), a modified version of MERA adapted for field theories, possesses a fixed point wave function with a nonzero Chern number. Additionally, it is well known that reversed MERA circuits can be used to prepare quantum states efficiently in time that scales logarithmically with the size of the system. However, state preparation via MERA typically requires the advent of a full-fledged universal quantum computer. In this Letter, we demonstrate that our cMERA circuit can potentially be realized in existing analog quantum computers, i.e., an ultracold atomic Fermi gas in an optical lattice with light-induced spin-orbit coupling.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.122.120502}, author = {Chu, Su-Kuan and Zhu, Guanyu and Garrison, James R. and Eldredge, Zachary and Curiel, Ana Valdes and Bienias, Przemyslaw and Spielman, I. B. and Gorshkov, V, Alexey} } @article { ISI:000501541900004, title = {Scanning tunneling Andreev microscopy of titanium nitride thin films}, journal = {Phys. Rev. B}, volume = {100}, number = {21}, year = {2019}, month = {DEC 9}, pages = {214505}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We report scanning tunneling microscopy results on 25- and 50-nm-thick films of superconducting TiN that show Andreev tunneling behavior at 0.5 K. At most locations on the topographically rough surfaces, we observe tip-sample current-voltage characteristics with a clear superconducting gap, as expected for superconductor-normal (S-N) tunneling through a low-transparency barrier, while in some places, we find a zero-voltage conductance peak, as expected for S-N Andreev tunneling through a highly transparent barrier. Fitting the Blonder-Tinkham-Klapwijk model to the conductance data allows an accurate extraction of the TiN superconducting gap Delta, by accounting for local variations in the tip-sample barrier height Z and junction temperature T. From spatial maps of the model parameters, we find that both films show a strong inhomogeneity, with Delta varying by as much as a factor of 2 from grain to grain. In the thicker film, however, correlations between T, Z, and Delta suggest the grains are thermally isolated, perhaps due to internal stress. We discuss possible mechanisms that could produce these large correlated variations, including local heating and surface contamination, and consider some of the implications for devices made from such films.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.214505}, author = {Liao, Wan-Ting and Kohler, T. P. and Osborn, K. D. and Butera, R. E. and Lobb, C. J. and Wellstood, F. C. and Dreyer, M.} } @article {ISI:000470849000068, title = {Silicon photonic add-drop filter for quantum emitters}, journal = {Opt. Express}, volume = {27}, number = {12}, year = {2019}, month = {JUN 10}, pages = {16882-16889}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {Integration of single-photon sources and detectors to silicon-based photonics opens the possibility of complex circuits for quantum information processing. In this work. we demonstrate integration of quantum dots with a silicon photonic add-drop filter for on-chip filtering and muting of telecom photons. A silicon microdisk resonator acts as a narrow filter that transfers the quantum dot emission and filters the background over a wide wavelength range. Moreover, by tuning the quantum dot emission wavelength over the resonance of the microdisk, we can control the transmission of the quantum dot emission to the drop and through channels of the add-drop filter. This result is a step toward the on-chip control of single photons using silicon photonics for applications in quantum information processing. such as linear optical quantum computation and boson sampling. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {1094-4087}, doi = {10.1364/OE.27.016882}, author = {Aghaeimeibodi, Shahriar and Kim, Je-Hyung and Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Richardson, Christopher and Waks, Edo} } @article {ISI:000478993000006, title = {Simulation of the coupling strength of capacitively coupled singlet-triplet qubits}, journal = {Phys. Rev. B}, volume = {100}, number = {7}, year = {2019}, month = {AUG 6}, pages = {075411}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We consider a system of two purely capacitively coupled singlet-triplet qubits and numerically simulate the energy structure of four electrons in two double quantum dots with a large potential barrier between them. We calculate the interqubit coupling strength using an extended Hund-Mulliken approach which includes excited orbitals in addition to the lowest-energy orbital for each quantum dot. We show the coupling strength as a function of the qubit separation as well as plotting it against the detunings of the two double quantum dots and show that the general qualitative features of our results can be captured by a potential-independent toy model of the system.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.075411}, author = {Buterakos, Donovan and Throckmorton, Robert E. and S. Das Sarma} } @article { ISI:000490353500045, title = {A Spin-Photon Interface Using Charge-Tunable Quantum Dots Strongly Coupled to a Cavity}, journal = {Nano Lett.}, volume = {19}, number = {10}, year = {2019}, month = {OCT}, pages = {7072-7077}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {Charged quantum dots containing an electron or hole spin are bright solid-state qubits suitable for quantum networks and distributed quantum computing. Incorporating such quantum dot spin into a photonic crystal cavity creates a strong spin-photon interface in which the spin can control a photon by modulating the cavity reflection coefficient. However, previous demonstrations of such spin-photon interfaces have relied on quantum dots that are charged randomly by nearby impurities, leading to instability in the charge state, which causes poor contrast in the cavity reflectivity. Here we demonstrate a strong spin-photon interface using a quantum dot that is charged deterministically with a diode structure. By incorporating this actively charged quantum dot in a photonic crystal cavity, we achieve strong coupling between the cavity mode and the negatively charged state of the dot. Furthermore, by initializing the spin through optical pumping, we show strong spin-dependent modulation of the cavity reflectivity, corresponding to a cooperativity of 12. This spin-dependent reflectivity is important for mediating entanglement between spins using photons, as well as generating strong photon-photon interactions for applications in quantum networking and distributed quantum computing.}, keywords = {cavity quantum electrodynamics, Quantum Dots, single electron spin, strong light-matter interaction}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.9b02443}, author = {Luo, Zhouchen and Sun, Shuo and Karasahin, Aziz and Bracker, Allan S. and Carter, Samuel G. and Yakes, Michael K. and Gammon, Daniel and Waks, Edo} } @article { ISI:000492332900005, title = {Stroboscopic approach to trapped-ion quantum information processing with squeezed phonons}, journal = {Phys. Rev. A}, volume = {100}, number = {4}, year = {2019}, month = {OCT 24}, pages = {043417}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {In trapped-ion quantum information processing, interactions between spins (qubits) are mediated by collective modes of motion of an ion crystal. While there are many different experimental strategies to design such interactions, they all face both technical and fundamental limitations to the achievable coherent interaction strength. In general, obtaining strong interactions and fast gates is an ongoing challenge. Here, we extend previous work {[}W. Ge, B. C. Sawyer, J. W. Britton, K. Jacobs, J. J. Bollinger, and M. Foss-Feig, Phys. Rev. Lett. 122, 030501 (2019)] and present a general strategy for enhancing the interaction strengths in trapped-ion systems via parametric amplification of the ions{\textquoteright} motion. Specifically, we propose a stroboscopic protocol using alternating applications of parametric amplification and spin-motion coupling. In comparison with the previous work, we show that the current protocol can lead to larger enhancements in the coherent interaction that increase exponentially with the gate time.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.043417}, author = {Ge, Wenchao and Sawyer, Brian C. and Britton, Joseph W. and Jacobs, Kurt and Foss-Feig, Michael and Bollinger, John J.} } @article { ISI:000492968000008, title = {Supercurrent interference in semiconductor nanowire Josephson junctions}, journal = {Phys. Rev. B}, volume = {100}, number = {15}, year = {2019}, month = {OCT 28}, pages = {155431}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Semiconductor-superconductor hybrid systems provide a promising platform for hosting unpaired Majorana fermions towards the realization of fault-tolerant topological quantum computing. In this study we employ the Keldysh nonequilibrium Green{\textquoteright}s function formalism to model quantum transport in normal-superconductor junctions. We analyze III-V semiconductor nanowire Josephson junctions (InAs/Nb) using a three-dimensional discrete lattice model described by the Bogoliubov-de Gennes Hamiltonian in the tight-binding approximation, and compute the Andreev bound state spectrum and current-phase relations. Recent experiments {[}Zuo et al., Phys. Rev. Lett. 119, 187704 (2017) and Gharavi et al., arXiv: 1405.7455] reveal critical current oscillations in these devices, and our simulations confirm these to be an interference effect of the transverse subbands in the nanowire. We add disorder to model coherent scattering and study its effect on the critical current oscillations, with an aim to gain a thorough understanding of the experiments. The oscillations in the disordered junction are highly sensitive to the particular realization of the random disorder potential, and to the gate voltage. A macroscopic current measurement thus gives us information about the microscopic profile of the junction. Finally, we study dephasing in the channel by including elastic phase-breaking interactions. The oscillations thus obtained are in good qualitative agreement with the experimental data, and this signifies the essential role of phase-breaking processes in III-V semiconductor nanowire Josephson junctions.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.155431}, author = {Sriram, Praveen and Kalantre, Sandesh S. and Gharavi, Kaveh and Baugh, Jonathan and Muralidharan, Bhaskaran} } @article {ISI:000479034100005, title = {Suppressing Inhomogeneous Broadening in a Lutetium Multi-ion Optical Clock}, journal = {Phys. Rev. Lett.}, volume = {123}, number = {6}, year = {2019}, month = {AUG 7}, pages = {063201}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We demonstrate precision measurement and control of inhomogeneous broadening in a multi-ion clock consisting of three Lu-176(+) ions. Microwave spectroscopy between hyperfine states in the D-3(1) level is used to characterize differential systematic shifts between ions, most notably those associated with the electric quadrupole moment. By appropriate alignment of the magnetic field, we demonstrate suppression of these effects to the similar to 10(-17) level relative to the S-1(0) <-> D-3(1) optical transition frequency. Correlation spectroscopy on the optical transition demonstrates the feasibility of a 10-s Ramsey interrogation in the three ion configuration with a corresponding projection noise limited stability of sigma(tau) = 8.2 x 10(-17)/root tau.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.123.063201}, author = {Tan, T. R. and Kaewuam, R. and Arnold, K. J. and Chanu, S. R. and Zhang, Zhiqiang and Safronova, M. S. and Barrett, M. D.} } @article {ISI:000461940700022, title = {Switchable detector array scheme to reduce the effect of single-photon detector{\textquoteright}s deadtime in a multi-bit/photon quantum link}, journal = {Opt. Commun.}, volume = {441}, year = {2019}, month = {JUN 15}, pages = {132-137}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, abstract = {{We explore the use of a switchable single-photon detector (SPD) array scheme to reduce the effect of a detector{\textquoteright}s deadtime for a multi-bit/photon quantum link. The case of data encoding using M possible orbital-angular-momentum (OAM) states is specifically studied in this paper. Our method uses N SPDs with a controllable M x N optical switch and we use a Monte Carlo-based method to simulate the quantum detection process. The simulation results show that with the use of the switchable SPD array, the detection system can allow a higher incident photon rate than what might otherwise be limited by detectors{\textquoteright} deadtime. For the case of M = 4}, keywords = {orbital angular momentum, quantum communication, Single photon detection}, issn = {0030-4018}, doi = {10.1016/j.optcom.2019.01.081}, author = {Liu, Cong and Ren, Yongxiong and Zhao, Jiapeng and Mirhosseini, Mohammad and Rafsanjani, Seyed Mohammad Hashemi and Xie, Guodong and Pang, Kai and Song, Haoqian and Zhao, Zhe and Wang, Zhe and Li, Long and Bienfang, Joshua C. and Migdall, Alan and Brun, Todd A. and Tur, Moshe and Boyd, Robert W. and Willner, Alan E.} } @article { ISI:000489831000001, title = {Synthetic Gauge Field for Two-Dimensional Time-Multiplexed Quantum Random Walks}, journal = {Phys. Rev. Lett.}, volume = {123}, number = {15}, year = {2019}, month = {OCT 11}, pages = {150503}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Temporal multiplexing provides an efficient and scalable approach to realize a quantum random walk with photons that can exhibit topological properties. But two-dimensional time-multiplexed topological quantum walks studied so far have relied on generalizations of the Su-Shreiffer-Heeger model with no synthetic gauge field. In this work, we demonstrate a two-dimensional topological quantum random walk where the nontrivial topology is due to the presence of a synthetic gauge field. We show that the synthetic gauge field leads to the appearance of multiple band gaps and, consequently, a spatial confinement of the quantum walk distribution. Moreover, we demonstrate topological edge states at an interface between domains with opposite synthetic fields. Our results expand the range of Hamiltonians that can be simulated using photonic quantum walks.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.123.150503}, author = {Chalabi, Hamidreza and Barik, Sabyasachi and Mittal, Sunil and Murphy, Thomas E. and Hafezi, Mohammad and Waks, Edo} } @conference {ISI:000482226302343, title = {Toward experimental implementation of quantum-enabled, bandwidth and power efficient communications}, booktitle = {2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2019}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 05-10, 2019}, publisher = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, organization = {IEEE; AdValue Photon; Amer Elements; Class5 Photon; Coherent; GoFoton; Light Convers; LightTrans; MKS; OZ Opt Online; Santec; ThorLabs; UQDevices; YSL Photon}, type = {Proceedings Paper}, abstract = {Coherent Frequency Shift Keying (CFSK) protocols paired with a quantum receiver can significantly optimize power and bandwidth efficiency of communication channels. We present our preliminary experimental data obtained with the CFSK quantum communication testbed. (c) 2019 The Author(s)}, isbn = {978-1-943580-57-6}, issn = {2160-9020}, author = {Burenkov, Ivan A. and Jabir, M. V. and El Idrissi, Driss and Battou, Abdella and Polyakov, Sergey V.} } @article {14841, title = {Training of quantum circuits on a hybrid quantum computer}, journal = {Science Advances}, volume = {5}, year = {2019}, abstract = {Generative modeling is a flavor of machine learning with applications ranging from computer vision to chemical design. It is expected to be one of the techniques most suited to take advantage of the additional resources provided by near-term quantum computers. Here, we implement a data-driven quantum circuit training algorithm on the canonical Bars-and-Stripes dataset using a quantum-classical hybrid machine. The training proceeds by running parameterized circuits on a trapped ion quantum computer and feeding the results to a classical optimizer. We apply two separate strategies, Particle Swarm and Bayesian optimization to this task. We show that the convergence of the quantum circuit to the target distribution depends critically on both the quantum hardware and classical optimization strategy. Our study represents the first successful training of a high-dimensional universal quantum circuit and highlights the promise and challenges associated with hybrid learning schemes.

}, doi = {10.1126/sciadv.aaw9918}, url = {https://advances.sciencemag.org/content/5/10/eaaw9918}, author = {Zhu, D. and Linke, N. M. and Benedetti, M. and Landsman, K. A. and Nguyen, N. H. and Alderete, C. H. and Perdomo-Ortiz, A. and Korda, N. and Garfoot, A. and Brecque, C. and Egan, L. and Perdomo, O. and Monroe, C.} } @article {ISI:000456782500003, title = {Trapped Ion Quantum Information Processing with Squeezed Phonons}, journal = {Phys. Rev. Lett.}, volume = {122}, number = {3}, year = {2019}, month = {JAN 24}, pages = {030501}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Trapped ions offer a pristine platform for quantum computation and simulation, but improving their coherence remains a crucial challenge. Here, we propose and analyze a new strategy to enhance the coherent interactions in trapped ion systems via parametric amplification of the ions{\textquoteright} motion-by squeezing the collective motional modes (phonons), the spin-spin interactions they mediate can be significantly enhanced. We illustrate the power of this approach by showing how it can enhance collective spin states useful for quantum metrology, and how it can improve the speed and fidelity of two-qubit gates in multi-ion systems, important ingredients for scalable trapped ion quantum computation. Our results are also directly relevant to numerous other physical platforms in which spin interactions are mediated by bosons.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.122.030501}, author = {Ge, Wenchao and Sawyer, Brian C. and Britton, Joseph W. and Jacobs, Kurt and Bollinger, John J. and Foss-Feig, Michael} } @article {ISI:000459152800093, title = {Twin-beam intensity-difference squeezing below 10 Hz}, journal = {Opt. Express}, volume = {27}, number = {4}, year = {2019}, month = {FEB 18}, pages = {4769-4780}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {We report the generation of strong, bright-beam intensity-difference squeezing down to measurement frequencies below 10 Hz. We generate two-mode squeezing in a four-wave mixing (4WM) process in Rb vapor, where the single-pass-gain nonlinear process does not require cavity locking and only relies on passive stability. We use diode laser technology and several techniques, including dual seeding, to remove the noise introduced by seeding the 4WM process as well as the background noise. Twin-beam intensity-difference squeezing down to frequencies limited only by the mechanical and atmospheric stability of the lab is achieved. These results should enable important low-frequency applications such as direct intensity-difference imaging with bright beams on integrating detectors. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {1094-4087}, doi = {10.1364/OE.27.004769}, author = {Wu, Meng-Chang and Schmittberger, Bonnie L. and Brewer, Nicholas R. and Speirs, Rory W. and Jones, Kevin M. and Lett, Paul D.} } @article {ISI:000455163900004, title = {Two-kind boson mixture honeycomb Hamiltonian of Bloch exciton-polaritons}, journal = {Phys. Rev. B}, volume = {99}, number = {4}, year = {2019}, month = {JAN 8}, pages = {045302}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {The electronic band structure of a solid is a collection of allowed bands separated by forbidden bands, revealing the geometric symmetry of the crystal structures. Comprehensive knowledge of the band structure with band parameters explains intrinsic physical, chemical, and mechanical properties of the solid. Here we report the artificial polaritonic band structures of two-dimensional honeycomb lattices for microcavity exciton-polaritons using GaAs semiconductors in the wide-range detuning values, from cavity photonlike (red-detuned) to excitonlike (blue-detuned) regimes. In order to understand the experimental band structures and their band parameters, such as gap energies, bandwidths, hopping integrals, and density of states, we originally establish a polariton band theory within an augmented plane wave method with two-kind bosons, cavity photons trapped at the lattice sites, and freely moving excitons. In particular, this two-kind band theory is absolutely essential to elucidate the exciton effect in the band structures of blue-detuned exciton-polaritons, where the flattened excitonlike dispersion appears at larger in-plane momentum values captured in our experimental access window. We reach an excellent agreement between theory and experiments in all detuning values.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.045302}, author = {Pan, Haining and Winkler, K. and Powlowski, Mats and Xie, Ming and Schade, A. and Emmerling, M. and Kamp, M. and Klembt, S. and Schneider, C. and Byrnes, Tim and Hoefling, S. and Kim, Na Young} } @article {ISI:000482579500007, title = {Two-qubit entangling gates within arbitrarily long chains of trapped ions}, journal = {Phys. Rev. A}, volume = {100}, number = {2}, year = {2019}, month = {AUG 26}, pages = {022332}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Ion trap quantum computers are based on modulating the Coulomb interaction between atomic ion qubits using external forces. However, the spectral crowding of collective motional modes could pose a challenge to the control of such interactions for large numbers of qubits. Here, we show that high-fidelity quantum gate operations are still possible with very large trapped ion crystals by using a small and fixed number of motional modes, simplifying the scaling of ion trap quantum computers. We present analytical work that shows that gate operations need not couple to the motion of distant ions, allowing parallel entangling gates with a crosstalk error that falls off as the inverse cube of the distance between the pairs. We also experimentally demonstrate high-fidelity entangling gates on a fully connected set of seventeen Yb-171(+) qubits using simple laser pulse shapes that primarily couple to just a few modes.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.022332}, author = {Landsman, K. A. and Wu, Y. and Leung, P. H. and Zhu, D. and Linke, N. M. and Brown, K. R. and Duan, L. and Monroe, C.} } @article {ISI:000482583200042, title = {Two-Terminal and Multi-Terminal Designs for Next-Generation Quantized Hall Resistance Standards: Contact Material and Geometry}, journal = {IEEE Trans. Electron Devices}, volume = {66}, number = {9}, year = {2019}, month = {SEP}, pages = {3973-3977}, publisher = {IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC}, type = {Article}, abstract = {In this paper, we show that quantum Hall resistance measurements using two terminals may be as precise as four-terminal measurements when applying superconducting split contacts. The described sample designs eliminate resistance contributions of terminals and contacts such that the size and complexity of next-generation quantized Hall resistance devices can be significantly improved.}, keywords = {Epitaxial graphene (EG), multi-series (MS) contacts, quantized Hall resistance (QHR) standards, quantum Hall effect (QHE), superconducting contacts}, issn = {0018-9383}, doi = {10.1109/TED.2019.2926684}, author = {Kruskopf, Mattias and Rigosi, Albert F. and Panna, Alireza R. and Patel, Dinesh K. and Jin, Hanbyul and Marzano, Martina and Berilla, Michael and Newell, David B. and Elmquist, Randolph E.} } @article {ISI:000482956700001, title = {Universal logical gates with constant overhead: instantaneous Dehn twists for hyperbolic quantum codes}, journal = {Quantum}, volume = {3}, year = {2019}, month = {JUL 26}, publisher = {VEREIN FORDERUNG OPEN ACCESS PUBLIZIERENS QUANTENWISSENSCHAF}, type = {Article}, abstract = {A basic question in the theory of fault-tolerant quantum computation is to understand the fundamental resource costs for performing a universal logical set of gates on encoded qubits to arbitrary accuracy. Here we consider qubits encoded with constant space overhead (i.e. finite encoding rate) in the limit of arbitrarily large code distance d through the use of topological codes associated to triangulations of hyperbolic surfaces. We introduce explicit protocols to demonstrate how Dehn twists of the hyperbolic surface can be implemented on the code through constant depth unitary circuits, without increasing the space overhead. The circuit for a given Dehn twist consists of a permutation of physical qubits, followed by a constant depth local unitary circuit, where locality here is defined with respect to a hyperbolic metric that defines the code. Applying our results to the hyperbolic Fibonacci Turaev-Viro code implies the possibility of applying universal logical gate sets on encoded qubits through constant depth unitary circuits and with constant space overhead. Our circuits are inherently protected from errors as they map local operators to local operators while changing the size of their support by at most a constant factor; in the presence of noisy syndrome measurements, our results suggest the possibility of universal fault tolerant quantum computation with constant space overhead and time overhead of O(d/log d). For quantum circuits that allow parallel gate operations, this yields the optimal scaling of space-time overhead known to date.}, issn = {2521-327X}, author = {Lavasani, Ali and Zhu, Guanyu and Barkeshli, Maissam} } @article { ISI:000490121400025, title = {Weakly bound molecules as sensors of new gravity like forces}, journal = {Sci Rep}, volume = {9}, year = {2019}, month = {OCT 15}, pages = {14807}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {Several extensions to the Standard Model of particle physics, including light dark matter candidates and unification theories predict deviations from Newton{\textquoteright}s law of gravitation. For macroscopic distances, the inverse-square law of gravitation is well confirmed by astrophysical observations and laboratory experiments. At micrometer and shorter length scales, however, even the state-of-the-art constraints on deviations from gravitational interaction, whether provided by neutron scattering or precise measurements of forces between macroscopic bodies, are currently many orders of magnitude larger than gravity itself. Here we show that precision spectroscopy of weakly bound molecules can be used to constrain non-Newtonian interactions between atoms. A proof-of-principle demonstration using recent data from photoassociation spectroscopy of weakly bound Yb-2 molecules yields constraints on these new interactions that are already close to state-of-the-art neutron scattering experiments. At the same time, with the development of the recently proposed optical molecular clocks, the neutron scattering constraints could be surpassed by at least two orders of magnitude.}, issn = {2045-2322}, doi = {10.1038/s41598-019-51346-y}, author = {Borkowski, Mateusz and Buchachenko, Alexei A. and Ciurylo, Roman and Julienne, Paul S. and Yamada, Hirotaka and Kikuchi, Yuu and Takasu, Yosuke and Takahashi, Yoshiro} } @article {ISI:000457732400002, title = {Wiedemann-Franz law and Fermi liquids}, journal = {Phys. Rev. B}, volume = {99}, number = {8}, year = {2019}, month = {FEB 4}, pages = {085104}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We consider in depth the applicability of the Wiedemann-Franz (WF) law, namely that the electronic thermal conductivity (K) is proportional to the product of the absolute temperature (T) and the electrical conductivity (a) in a metal with the constant of proportionality, the so-called Lorenz number L-0, being a materials-independent universal constant in all systems obeying the Fermi liquid (FL) paradigm. It has been often stated that the validity (invalidity) of the WF law is the hallmark of an FL {[}non-Fermi liquid (NFL)]. We consider, both in two (2D) and three (3D) dimensions, a system of conduction electrons at a finite temperature T coupled to a bath of acoustic phonons and quenched impurities, ignoring effects of electron-electron interactions. We find that the WF law is violated arbitrarily strongly with the effective Lorenz number vanishing at low temperatures as long as phonon scattering is stronger than impurity scattering. This happens both in 2D and in 3D for T < T-BG, where T-BG is the Bloch-Griineisen temperature of the system. In the absence of phonon scattering (or equivalently, when impurity scattering is much stronger than the phonon scattering), however, the WF law is restored at low temperatures even if the impurity scattering is mostly small angle forward scattering. Thus, strictly at T = 0 the WF law is always valid in a FL in the presence of infinitesimal impurity scattering. For strong phonon scattering, the WF law is restored for T > T-BG (or the Debye temperature T-D, whichever is lower) as in usual metals. At very high temperatures, thermal smearing of the Fermi surface causes the effective Lorenz number to go below L-0, manifesting a quantitative deviation from the WF law. Our paper establishes definitively that the uncritical association of an NFL behavior with the failure of the WF law is incorrect.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.99.085104}, author = {Lavasani, Ali and Bulmash, Daniel and S. Das Sarma} } @article { ISI:000433962700091, title = {A 3D-printed alkali metal dispenser}, journal = {REVIEW OF SCIENTIFIC INSTRUMENTS}, volume = {89}, number = {5}, year = {2018}, month = {MAY}, pages = {056101}, issn = {0034-6748}, doi = {10.1063/1.5023906}, author = {Norrgard, E. B. and Barker, D. S. and Fedchak, J. A. and Klimov, N. and Scherschligt, J. and Eckel, S.} } @article {ISI:000431374900011, title = {Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal}, journal = {SCIENCE ADVANCES}, volume = {4}, number = {4}, year = {2018}, month = {APR}, pages = {eaao4513}, publisher = {AMER ASSOC ADVANCEMENT SCIENCE}, type = {Article}, abstract = {In all known fermionic superfluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to formeither spinsinglet or spin-triplet bound states. The {\textquoteleft}{\textquoteleft}spin{{\textquoteright}{\textquoteright}} of a Bloch electron, however, is fixed by the symmetries of the crystal and the atomic orbitals from which it is derived and, in some cases, can behave as if it were a spin-3/2 particle. The superconducting state of such a system allows pairing beyond spin-triplet, with higher spin quasi-particles combining to formquintet or septet pairs. We report evidence of unconventional superconductivity emerging from a spin-3/2 quasi-particle electronic structure in the half-Heusler semimetal YPtBi, a low-carrier density noncentrosymmetric cubic material with a high symmetry that preserves the p-like j = 3/2 manifold in the Bi-based Gamma(8) band in the presence of strong spin-orbit coupling. With a striking linear temperature dependence of the London penetration depth, the existence of line nodes in the superconducting order parameter Delta is directly explained by a mixed-parity Cooper pairing model with high total angular momentum, consistent with a high-spin fermionic superfluid state. We propose a k.p model of the j = 3/2 fermions to explain how a dominant J = 3 septet pairing state is the simplest solution that naturally produces nodes in the mixed even-odd parity gap. Together with the underlying topologically nontrivial band structure, the unconventional pairing in this system represents a truly novel form of superfluidity that has strong potential for leading the development of a new series of topological superconductors.

}, issn = {2375-2548}, doi = {10.1126/sciadv.aao4513}, author = {Kim, Hyunsoo and Wang, Kefeng and Nakajima, Yasuyuki and Hu, Rongwei and Ziemak, Steven and Syers, Paul and Wang, Limin and Hodovanets, Halyna and Denlinger, Jonathan D. and Brydon, Philip M. R. and Agterberg, Daniel F. and Tanatar, Makariy A. and Prozorov, Ruslan and Paglione, Johnpierre} } @article { ISI:000444740400001, title = {Challenges to miniaturizing cold atom technology for deployable vacuum metrology}, journal = {METROLOGIA}, volume = {55}, number = {5}, year = {2018}, month = {OCT}, pages = {S182-S193}, keywords = {cold atom sensing, quantum-SI, vacuum metrology}, issn = {0026-1394}, doi = {10.1088/1681-7575/aadbe4}, author = {Eckel, Stephen and Barker, Daniel S. and Fedchak, James A. and Klimov, Nikolai N. and Norrgard, Eric and Scherschligt, Julia and Makrides, Constantinos and Tiesinga, Eite} } @article { ISI:000445336700001, title = {Chiral Majorana fermion modes on the surface of superconducting topological insulators}, journal = {EPL}, volume = {123}, number = {4}, year = {2018}, month = {AUG}, pages = {47005}, issn = {0295-5075}, doi = {10.1209/0295-5075/123/47005}, author = {Chiu, Ching-Kai and Bian, Guang and Zheng, Hao and Yin, Jia-Xin and Zhang, Songtian S. and Sanchez, D. S. and Belopolski, I and Xu, Su-Yang and Hasan, M. Zahid} } @article { ISI:000428617600038, title = {A coherent spin-photon interface in silicon}, journal = {NATURE}, volume = {555}, number = {7698}, year = {2018}, month = {MAR 29}, pages = {599+}, issn = {0028-0836}, doi = {10.1038/nature25769}, author = {Mi, X. and Benito, M. and Putz, S. and Zajac, D. M. and Taylor, J. M. and Burkard, Guido and Petta, J. R.} } @article { ISI:000423614600001, title = {Controlling the layer localization of gapless states in bilayer graphene with a gate voltage}, journal = {2D MATERIALS}, volume = {5}, number = {2}, year = {2018}, month = {APR}, pages = {025006}, keywords = {bilayer graphene, graphene, topologically protected states}, issn = {2053-1583}, doi = {10.1088/2053-1583/aaa490}, author = {Jaskolski, W. and Pelc, M. and Bryant, Garnett W. and Chico, Leonor and Ayuela, A.} } @article { ISI:000449713800005, title = {Coupling quantum emitters in WSe2 monolayers to a metal-insulator-metal waveguide}, journal = {APPLIED PHYSICS LETTERS}, volume = {113}, number = {19}, year = {2018}, month = {NOV 5}, pages = {191105}, issn = {0003-6951}, doi = {10.1063/1.5045727}, author = {Dutta, Subhojit and Cai, Tao and Buyukkaya, Mustafa Atabey and Barik, Sabyasachi and Aghaeimeibodi, Shahriar and Waks, Edo} } @article { ISI:000423433700007, title = {Crosstalk error correction through dynamical decoupling of single-qubit gates in capacitively coupled singlet-triplet semiconductor spin qubits}, journal = {PHYSICAL REVIEW B}, volume = {97}, number = {4}, year = {2018}, month = {JAN 29}, pages = {045431}, issn = {2469-9950}, doi = {10.1103/PhysRevB.97.045431}, author = {Buterakos, Donovan and Throckmorton, Robert E. and S. Das Sarma} } @article {9151, title = {Dark State Optical Lattice with a Subwavelength Spatial Structure}, journal = {Phys. Rev. Lett.}, volume = {120}, year = {2018}, month = {Feb}, pages = {083601}, doi = {10.1103/PhysRevLett.120.083601}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.120.083601}, author = {Wang, Y. and Subhankar, S. and Bienias, P and {\L}{\k a}cki, M. and Tsui, T-C. and Baranov, M. A. and Gorshkov, A. V. and Zoller, P. and Porto, J. V. and Rolston, S. L.} } @article { ISI:000439334800001, title = {Demonstration of a Bayesian quantum game on an ion-trap quantum computer}, journal = {QUANTUM SCIENCE AND TECHNOLOGY}, volume = {3}, number = {4}, year = {2018}, month = {OCT}, pages = {UNSP 045002}, keywords = {ion traps, quantum computation, quantum games}, issn = {2058-9565}, doi = {10.1088/2058-9565/aacf0e}, author = {Solmeyer, Neal and Linke, Norbert M. and Figgatt, Caroline and Landsman, Kevin A. and Balu, Radhakrishnan and Siopsis, George and Monroe, C.} } @article {ISI:000426249900005, title = {Dissipation-induced dipole blockade and antiblockade in driven Rydberg systems}, journal = {PHYSICAL REVIEW A}, volume = {97}, number = {2}, year = {2018}, month = {FEB 28}, pages = {023424}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study theoretically and experimentally the competing blockade and antiblockade effects induced by spontaneously generated contaminant Rydberg atoms in driven Rydberg systems. These contaminant atoms provide a source of strong dipole-dipole interactions and play a crucial role in the system{\textquoteright}s behavior. We study this problem theoretically using two different approaches. The first is a cumulant expansion approximation, in which we ignore third-order and higher connected correlations. Using this approach for the case of resonant drive, a many-body blockade radius picture arises, and we find qualitative agreement with previous experimental results. We further predict that as the atomic density is increased, the Rydberg population{\textquoteright}s dependence on Rabi frequency will transition from quadratic to linear dependence at lower Rabi frequencies. We study this behavior experimentally by observing this crossover at two different atomic densities. We confirm that the larger density system has a smaller crossover Rabi frequency than the smaller density system. The second theoretical approach is a set of phenomenological inhomogeneous rate equations. We compare the results of our rate-equation model to the experimental observations {[}E. A. Goldschmidt et al., Phys. Rev. Lett. 116, 113001 (2016)] and find that these rate equations provide quantitatively good scaling behavior of the steady-state Rydberg population for both resonant and off-resonant drives.}, \%\%Address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, issn = {2469-9926}, doi = {10.1103/PhysRevA.97.023424}, author = {Young, Jeremy T. and Boulier, Thomas and Magnan, Eric and Goldschmidt, Elizabeth A. and Wilson, Ryan M. and Rolston, Steven L. and Porto, James V. and Gorshkov, Alexey V.} } @article { ISI:000437843700001, title = {Effective renormalized multi-body interactions of harmonically confined ultracold neutral bosons (vol 14, 053037, 2012)}, journal = {NEW JOURNAL OF PHYSICS}, volume = {20}, year = {2018}, month = {JUL 6}, pages = {079501}, issn = {1367-2630}, doi = {10.1088/1367-2630/aacf78}, author = {Johnson, P. R. and Blume, D. and Yin, X. Y. and Flynn, W. F. and Tiesinga, E.} } @article { ISI:000451073900001, title = {Equations of state from individual one-dimensional Bose gases}, journal = {NEW JOURNAL OF PHYSICS}, volume = {20}, year = {2018}, month = {NOV 23}, pages = {113032}, abstract = {We trap individual 1D Bose gases and obtain the associated equation of state by combining calibrated confining potentials with in situ density profiles. Our observations agree well with the exact Yang- Yang 1D thermodynamic solutions under the local density approximation. We find that our final 1D system undergoes inefficient evaporative cooling that decreases the absolute temperature, but monotonically reduces a degeneracy parameter.}, keywords = {atomic physics, equation of state, one-dimensonal Bose gas, quantum gases}, issn = {1367-2630}, doi = {10.1088/1367-2630/aaef9b}, author = {Salces-Carcoba, F. and Billington, C. J. and Putra, A. and Yue, Y. and Sugawa, S. and Ian B Spielman} } @article { ISI:000437110200003, title = {Error correction for gate operations in systems of exchange-coupled singlet-triplet qubits in double quantum dots}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {3}, year = {2018}, month = {JUL 3}, pages = {035406}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.035406}, author = {Buterakos, Donovan and Throckmorton, Robert E. and S. Das Sarma} } @article { ISI:000433265900009, title = {Examining epitaxial graphene surface conductivity and quantum Hall device stability with Parylene passivation}, journal = {MICROELECTRONIC ENGINEERING}, volume = {194}, year = {2018}, month = {JUL 5}, pages = {51-55}, keywords = {epitaxial graphene, Parylene, quantum Hall effect, Surface conductivity, Transport mobility}, issn = {0167-9317}, doi = {10.1016/j.mee.2018.03.004}, author = {Rigosi, Albert F. and Liu, Chieh-I and Wu, Bi Yi and Lee, Hsin-Yen and Kruskopf, Mattias and Yang, Yanfei and Hill, Heather M. and Hu, Jiuning and Bittle, Emily G. and Obrzut, Jan and Walker, Angela R. Hight and Elmquist, Randolph E. and Newell, David B.} } @article { ISI:000448933900006, title = {Fractional Quantum Hall Effect at nu=2+6/13: The Parton Paradigm for the Second Landau Level}, journal = {PHYSICAL REVIEW LETTERS}, volume = {121}, number = {18}, year = {2018}, month = {NOV 1}, pages = {186601}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.121.186601}, author = {Balram, Ajit C. and Mukherjee, Sutirtha and Park, Kwon and Barkeshli, Maissam and Rudner, Mark S. and Jain, J. K.} } @article {10546, title = {Fractional Quantum Hall Phases of Bosons with Tunable Interactions: From the Laughlin Liquid to a Fractional Wigner Crystal}, journal = {Phys. Rev. Lett.}, volume = {121}, year = {2018}, month = {Dec}, pages = {253403}, doi = {10.1103/PhysRevLett.121.253403}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.121.253403}, author = {Gra{\ss}, Tobias and Bienias, Przemyslaw and Gullans, Michael J. and Lundgren, Rex and Maciejko, Joseph and Gorshkov, Alexey V.} } @article { ISI:000434628400002, title = {Higgs mechanism in higher-rank symmetric U(1) gauge theories}, journal = {PHYSICAL REVIEW B}, volume = {97}, number = {23}, year = {2018}, month = {JUN 8}, pages = {235112}, issn = {2469-9950}, doi = {10.1103/PhysRevB.97.235112}, author = {Bulmash, Daniel and Barkeshli, Maissam} } @article { ISI:000425091300007, title = {High-fidelity quantum gates in Si/SiGe double quantum dots}, journal = {PHYSICAL REVIEW B}, volume = {97}, number = {8}, year = {2018}, month = {FEB 15}, pages = {085421}, issn = {2469-9950}, doi = {10.1103/PhysRevB.97.085421}, author = {Russ, Maximilian and Zajac, D. M. and Sigillito, A. J. and Borjans, F. and Taylor, J. M. and Petta, J. R. and Burkard, Guido} } @article { ISI:000451739700002, title = {Integration of quantum dots with lithium niobate photonics}, journal = {APPLIED PHYSICS LETTERS}, volume = {113}, number = {22}, year = {2018}, month = {NOV 26}, pages = {221102}, abstract = {The integration of quantum emitters with integrated photonics enables complex quantum photonic circuits that are necessary for photonic implementation of quantum simulators, computers, and networks. Thin-film lithium niobate is an ideal material substrate for quantum photonics because it can tightly confine light in small waveguides and has a strong electro-optic effect that can switch and modulate single photons at low power and high speed. However, lithium niobate lacks efficient single-photon emitters, which are essential for scalable quantum photonic circuits. We demonstrate deterministic coupling of single-photon emitters with a lithium niobate photonic chip. The emitters are composed of InAs quantum dots embedded in an InP nanobeam, which we transfer to a lithium niobate waveguide with nanoscale accuracy using a pick-and-place approach. An adiabatic taper transfers single photons emitted into the nanobeam to the lithium niobate waveguide with high efficiency. We verify the single photon nature of the emission using photon correlation measurements performed with an on-chip beamsplitter. Our results demonstrate an important step toward fast, reconfigurable quantum photonic circuits for quantum information processing. Published by AIP Publishing.}, issn = {0003-6951}, doi = {10.1063/1.5054865}, author = {Aghaeimeibodi, Shahriar and Desiatov, Boris and Kim, Je-Hyung and Lee, Chang-Min and Buyukkaya, Mustafa Atabey and Karasahin, Aziz and Richardson, Christopher J. K. and Leavitt, Richard P. and Loncar, Marko and Waks, Edo} } @article { ISI:000447148100013, title = {Long spin-flip time and large Zeeman splitting of holes in type-II ZnTe/ZnSe submonolayer quantum dots}, journal = {JOURNAL OF APPLIED PHYSICS}, volume = {124}, number = {14}, year = {2018}, month = {OCT 14}, pages = {144306}, issn = {0021-8979}, doi = {10.1063/1.5041478}, author = {Ji, H. and Dhomkar, S. and Wu, R. and Ludwig, J. and Lu, Z. and Smirnov, D. and Tamargo, M. C. and Bryant, G. W. and Kuskovsky, I. L.} } @article { ISI:000450258700003, title = {Low overhead Clifford gates from joint measurements in surface, color, and hyperbolic codes}, journal = {PHYSICAL REVIEW A}, volume = {98}, number = {5}, year = {2018}, month = {NOV 15}, pages = {052319}, issn = {2469-9926}, doi = {10.1103/PhysRevA.98.052319}, author = {Lavasani, Ali and Barkeshli, Maissam} } @article { ISI:000440590200010, title = {A low-steering piezo-driven mirror}, journal = {REVIEW OF SCIENTIFIC INSTRUMENTS}, volume = {89}, number = {7}, year = {2018}, month = {JUL}, pages = {073110}, issn = {0034-6748}, doi = {10.1063/1.5035326}, author = {Magnan, E. and Maslek, J. and Bracamontes, C. and Restelli, A. and Boulier, T. and Porto, J. V.} } @article { ISI:000418043100001, title = {Measuring the dielectric and optical response of millimeter-scale amorphous and hexagonal boron nitride films grown on epitaxial graphene}, journal = {2D MATERIALS}, volume = {5}, number = {1}, year = {2018}, month = {JAN}, pages = {011011}, keywords = {amorphous boron nitride, epitaxial graphene, hexagonal boron nitride, optical dielectric functions}, issn = {2053-1583}, doi = {10.1088/2053-1583/aa9ea3}, author = {Rigosi, Albert F. and Hill, Heather M. and Glavin, Nicholas R. and Pookpanratana, Sujitra J. and Yang, Yanfei and Boosalis, Alexander G. and Hu, Jiuning and Rice, Anthony and Allerman, Andrew A. and Nguyen, Nhan V. and Hacker, Christina A. and Elmquist, Randolph E. and Walker, Angela R. Hight and Newell, David B.} } @article { ISI:000425707400027, title = {A model for metastable magnetism in the hidden-order phase of URu2Si2}, journal = {ANNALS OF PHYSICS}, volume = {388}, year = {2018}, month = {JAN}, pages = {398-407}, keywords = {Ginzburg-Landau theory, Heavy fermion, Hidden order, Kerr effect}, issn = {0003-4916}, doi = {10.1016/j.aop.2017.11.024}, author = {Boyer, Lance and Yakovenko, Victor M.} } @article { ISI:000447301700001, title = {Optical control over bulk excitations in fractional quantum Hall systems}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {15}, year = {2018}, month = {OCT 15}, pages = {155124}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.155124}, author = {Grass, Tobias and Gullans, Michael and Bienias, Przemyslaw and Zhu, Guanyu and Ghazaryan, Areg and Ghaemi, Pouyan and Hafezi, Mohammad} } @article { ISI:000439057800004, title = {Parton construction of a wave function in the anti-Pfaffian phase}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {3}, year = {2018}, month = {JUL 18}, pages = {035127}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.035127}, author = {Balram, Ajit C. and Barkeshli, Maissam and Rudner, Mark S.} } @article {ISI:000427318600005, title = {Photon Subtraction by Many-Body Decoherence}, journal = {PHYSICAL REVIEW LETTERS}, volume = {120}, number = {11}, year = {2018}, month = {MAR 13}, pages = {113601}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We experimentally and theoretically investigate the scattering of a photonic quantum field from another stored in a strongly interacting atomic Rydberg ensemble. Considering the many-body limit of this problem, we derive an exact solution to the scattering-induced spatial decoherence of multiple stored photons, allowing for a rigorous understanding of the underlying dissipative quantum dynamics. Combined with our experiments, this analysis reveals a correlated coherence-protection process in which the scattering from one excitation can shield all others from spatial decoherence. We discuss how this effect can be used to manipulate light at the quantum level, providing a robust mechanism for single-photon subtraction, and experimentally demonstrate this capability.}, \%\%Address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.120.113601}, author = {Murray, C. R. and Mirgorodskiy, I. and Tresp, C. and Braun, C. and Paris-Mandoki, A. and Gorshkov, A. V. and Hofferberth, S. and Pohl, T.} } @article { ISI:000452612200037, title = {A post-processing-free single-photon random number generator with ultra-low latency}, journal = {OPTICS EXPRESS}, volume = {26}, number = {25}, year = {2018}, month = {DEC 10}, pages = {32788-32801}, abstract = {The low-latency requirements of a practical loophole-free Bell test preclude time-consuming post-processing steps that are often used to improve the statistical quality of a physical random number generator (RNG). Here we demonstrate a post-processing-free RNG that produces a random bit within 2.4(2) ns of an input trigger. We use weak feedback to eliminate long-term drift, resulting in 24 hour operation with output that is statistically indistinguishable from a Bernoulli process. We quantify the impact of the feedback on the predictability of the output as less than 6.4x10(-7) and demonstrate the utility of the Allan variance as a tool for characterizing non-idealities in RNGs. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {1094-4087}, doi = {10.1364/OE.26.032788}, author = {Wayne, Michael A. and Migdall, Alan L. and Levine, Zachary H. and Bienfang, Joshua C.} } @article { ISI:000434633000006, title = {Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy}, journal = {PHYSICAL REVIEW LETTERS}, volume = {120}, number = {23}, year = {2018}, month = {JUN 8}, pages = {232503}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.120.232503}, author = {Raeder, S. and Ackermann, D. and Backe, H. and Beerwerth, R. and Berengut, J. C. and Block, M. and Borschevsky, A. and Cheal, B. and Chhetri, P. and Duellmann, Ch. E. and Dzuba, V. A. and Eliav, E. and Even, J. and Ferrer, R. and flambaum, v. v. and Fritzsche, S. and Giacoppo, F. and Goetz, S. and Hessberger, F. P. and Huyse, M. and Kaldor, U. and Kaleja, O. and Khuyagbaatar, J. and Kunz, P. and Laatiaoui, M. and Lautenschlager, F. and Lauth, W. and Mistry, A. K. and Ramirez, E. Minaya and Nazarewicz, W. and Porsev, S. G. and Safronova, M. S. and Safronova, U. I. and Schuetrumpf, B. and Van Duppen, P. and Walther, T. and Wraith, C. and Yakushev, A.} } @article {9191, title = {Quantized Majorana conductance}, journal = {Nature}, volume = {Advanced Online Publication}, year = {2018}, month = {03/2018}, url = {http://dx.doi.org/10.1038/nature26142}, author = {Zhang, Hao and Liu, Chun-Xiao and Gazibegovic, Sasa and Xu, Di and Logan, John A. and Wang, Guanzhong and van Loo, Nick and Bommer, Jouri D. S. and de Moor, Michiel W. A. and Car, Diana and Op het Veld, Roy L. M. and van Veldhoven, Petrus J. and Koelling, Sebastian and Verheijen, Marcel A. and Pendharkar, Mihir and Pennachio, Daniel J. and Shojaei, Borzoyeh and Lee, Joon Sue and Palmstr{\o}m, Chris J. and Bakkers, Erik P. A. M. and S. Das Sarma and Kouwenhoven, Leo P.} } @article { ISI:000450242200180, title = {Quantum Hall device data monitoring following encapsulating polymer deposition}, journal = {DATA IN BRIEF}, volume = {20}, year = {2018}, month = {OCT}, pages = {1201-1208}, issn = {2352-3409}, doi = {10.1016/j.dib.2018.08.121}, author = {Rigosi, Albert F. and Liu, Chieh-I and Wu, Bi Yi and Lee, Hsin-Yen and Kruskopf, Mattias and Yang, Yanfei and Hill, Heather M. and Hu, Jiuning and Bittle, Emily G. and Obrzut, Jan and Walker, Angela R. Hight and Elmquist, Randolph E. and Newell, David B.} } @article { ISI:000428145500001, title = {Quantum receiver for large alphabet communication}, journal = {OPTICA}, volume = {5}, number = {3}, year = {2018}, month = {MAR 20}, pages = {227-232}, issn = {2334-2536}, doi = {10.1364/OPTICA.5.000227}, author = {Burenkov, I. A. and Tikhonova, O. V. and Polyakov, S. V.} } @article { ISI:000423283200042, title = {Resonantly driven CNOT gate for electron spins}, journal = {SCIENCE}, volume = {359}, number = {6374}, year = {2018}, month = {JAN 26}, pages = {439-442}, issn = {0036-8075}, doi = {10.1126/science.aao5965}, author = {Zajac, D. M. and Sigillito, A. J. and Russ, M. and Borjans, F. and Taylor, J. M. and Burkard, G. and Petta, J. R.} } @article { ISI:000419619800001, title = {Robust 2-Qubit Gates in a Linear Ion Crystal Using a Frequency-Modulated Driving Force}, journal = {PHYSICAL REVIEW LETTERS}, volume = {120}, number = {2}, year = {2018}, month = {JAN 9}, pages = {020501}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.120.020501}, author = {Leung, Pak Hong and Landsman, Kevin A. and Figgatt, Caroline and Linke, Norbert M. and Monroe, Christopher and Brown, Kenneth R.} } @article { ISI:000436944600001, title = {Search for new physics with atoms and molecules}, journal = {REVIEWS OF MODERN PHYSICS}, volume = {90}, number = {2}, year = {2018}, month = {JUN 29}, pages = {025008}, issn = {0034-6861}, doi = {10.1103/RevModPhys.90.025008}, author = {Safronova, M. S. and Budker, D. and DeMille, D. and Kimball, Derek F. Jackson and Derevianko, A. and Clark, Charles W.} } @article { ISI:000430383200001, title = {Single-Particle Mobility Edge in a One-Dimensional Quasiperiodic Optical Lattice}, journal = {PHYSICAL REVIEW LETTERS}, volume = {120}, number = {16}, year = {2018}, month = {APR 19}, pages = {160404}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.120.160404}, author = {Luschen, Henrik P. and Scherg, Sebastian and Kohlert, Thomas and Schreiber, Michael and Bordia, Pranjal and Li, Xiao and S. Das Sarma and Bloch, Immanuel} } @article {ISI:000419619800004, title = {Spectrum Estimation of Density Operators with Alkaline-Earth Atoms}, journal = {PHYSICAL REVIEW LETTERS}, volume = {120}, number = {2}, year = {2018}, month = {JAN 9}, pages = {025301}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We show that Ramsey spectroscopy of fermionic alkaline-earth atoms in a square-well trap provides an efficient and accurate estimate for the eigenspectrum of a density matrix whose n copies are stored in the nuclear spins of n such atoms. This spectrum estimation is enabled by the high symmetry of the interaction Hamiltonian, dictated, in turn, by the decoupling of the nuclear spin from the electrons and by the shape of the square-well trap. Practical performance of this procedure and its potential applications to quantum computing and time keeping with alkaline-earth atoms are discussed.}, \%\%Address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.120.025301}, author = {Beverland, Michael E. and Haah, Jeongwan and Alagic, Gorjan and Campbell, Gretchen K. and Rey, Ana Maria and Gorshkov, Alexey V.} } @article { ISI:000452316100001, title = {Spin decoherence in a two-qubit CPHASE gate: the critical role of tunneling noise}, journal = {NPJ QUANTUM INFORMATION}, volume = {4}, year = {2018}, month = {NOV 27}, pages = {62}, abstract = {Rapid progress in semiconductor spin qubits has enabled experimental demonstrations of a two-qubit logic gate. Understanding spin decoherence in a two-qubit logic gate is necessary for optimal qubit operation. We study spin decoherence due to 1/f charge noise for two electrons in a double quantum dot used for a two-qubit controlled-phase gate. In contrast to the usual belief, spin decoherence can be dominated by the tunneling noise from 1/f charge noise instead of the detuning noise. Tunneling noise can dominate because the effect of tunneling noise on the spin qubit is first order in the charge admixture; while the effect of the detuning noise is only second order. The different orders of contributions result in different detuning dependence of the decoherence, which provides a way to identify the noise source. We find that decoherence in a recent two-qubit experiment was dominated by the tunneling noise from 1/f charge noise. The results illustrate the importance of considering tunneling noise to design optimal operation of spin qubits.}, issn = {2056-6387}, doi = {10.1038/s41534-018-0112-0}, author = {Huang, Peihao and Zimmerman, Neil M. and Bryant, Garnett W.} } @article { ISI:000450547500006, title = {Spin relaxation of a donor electron coupled to interface states}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {19}, year = {2018}, month = {NOV 16}, pages = {195307}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.195307}, author = {Huang, Peihao and Bryant, Garnett W.} } @article { ISI:000453476900018, title = {Spin-Mechanical Coupling of an InAs Quantum Dot Embedded in a Mechanical Resonator}, journal = {PHYSICAL REVIEW LETTERS}, volume = {121}, number = {24}, year = {2018}, month = {DEC 14}, pages = {246801}, abstract = {We demonstrate strain-induced coupling between a hole spin in a quantum dot and mechanical motion of a cantilever. The optical transitions of quantum dots integrated into GaAs mechanical resonators are measured synchronously with the motion of the driven resonators. In a Voigt magnetic field, both electron and hole spin splittings are measured, showing negligible change for the electron spin but a large change for the hole spin of up to 36\%. This large effect is attributed to the stronger spin orbit interaction of holes compared to electrons.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.121.246801}, author = {Carter, S. G. and Bracker, A. S. and Bryant, G. W. and Kim, M. and Kim, C. S. and Zalalutdinov, M. K. and Yakes, M. K. and Czarnocki, C. and Casara, J. and Scheibner, M. and Gammon, D.} } @article { ISI:000441857400004, title = {Spinor Bose-Einstein-condensate phase-sensitive amplifier for SU(1,1) interferometry}, journal = {PHYSICAL REVIEW A}, volume = {98}, number = {2}, year = {2018}, month = {AUG 16}, pages = {023620}, issn = {2469-9926}, doi = {10.1103/PhysRevA.98.023620}, author = {Wrubel, J. P. and Schwettmann, A. and Fahey, D. P. and Glassman, Z. and Pechkis, H. K. and Griffin, P. F. and Barnett, R. and Tiesinga, E. and Lett, P. D.} } @article { ISI:000448599200008, title = {Structure of correlated worldline theories of quantum gravity}, journal = {PHYSICAL REVIEW D}, volume = {98}, number = {8}, year = {2018}, month = {OCT 29}, pages = {084052}, issn = {2470-0010}, doi = {10.1103/PhysRevD.98.084052}, author = {Barvinsky, A. O. and Carney, D. and Stamp, P. C. E.} } @article { ISI:000444775000003, title = {Time-reversal and spatial-reflection symmetry localization anomalies in (2+1)-dimensional topological phases of matter}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {11}, year = {2018}, month = {SEP 17}, pages = {115129}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.115129}, author = {Barkeshli, Maissam and Cheng, Meng} } @article { ISI:000437838000015, title = {Topological Exciton Fermi Surfaces in Two-Component Fractional Quantized Hall Insulators}, journal = {PHYSICAL REVIEW LETTERS}, volume = {121}, number = {2}, year = {2018}, month = {JUL 9}, pages = {026603}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.121.026603}, author = {Barkeshli, Maissam and Nayak, Chetan and Papic, Zlatko and Young, Andrea and Zaletel, Michael} } @article {8956, title = {A topological quantum optics interface}, journal = {Science}, volume = {359}, year = {2018}, chapter = {666}, doi = {10.1126/science.aaq0327}, url = {http://science.sciencemag.org/content/359/6376/666}, author = {Barik, Sabyasachi and Aziz Karasahin and Christopher Flower and Cai, Tao and Miyake, H. and DeGottardi, Wade and Mohammad Hafezi and Edo Waks} } @article { ISI:000440602300120, title = {Towards superconductivity in p-type delta-doped Si/Al/Si heterostructures}, journal = {AIP ADVANCES}, volume = {8}, number = {7}, year = {2018}, month = {JUL}, pages = {075329}, issn = {2158-3226}, doi = {10.1063/1.5045338}, author = {Ramanayaka, A. N. and Kim, Hyun-Soo and Hagmann, J. A. and Murray, R. E. and Tang, Ke and Meisenkothen, F. and Zhang, H. R. and Bendersky, L. A. and Davydov, A. V. and Zimmerman, Neil M. and Richter, C. A. and Pomeroy, J. M.} } @article { ISI:000435178200017, title = {Two-frequency operation of a Paul trap to optimise confinement of two species of ions}, journal = {INTERNATIONAL JOURNAL OF MASS SPECTROMETRY}, volume = {430}, year = {2018}, month = {JUL}, pages = {117-125}, keywords = {Ion trap, Multiple frequencies, Parametric heating}, issn = {1387-3806}, doi = {10.1016/j.ijms.2018.05.007}, author = {Foot, C. J. and Trypogeorgos, D. and Bentine, E. and Gardner, A. and Keller, M.} } @article { ISI:000423107800027, title = {Ultracold atoms in multiple radio-frequency dressed adiabatic potentials}, journal = {PHYSICAL REVIEW A}, volume = {97}, number = {1}, year = {2018}, month = {JAN 16}, pages = {013616}, issn = {2469-9926}, doi = {10.1103/PhysRevA.97.013616}, author = {Harte, T. L. and Bentine, E. and Luksch, K. and Barker, A. J. and Trypogeorgos, D. and Yuen, B. and Foot, C. J.} } @article { ISI:000454419500004, title = {Unitary entanglement construction in hierarchical networks}, journal = {PHYSICAL REVIEW A}, volume = {98}, number = {6}, year = {2018}, month = {DEC 26}, pages = {062328}, abstract = {The construction of large-scale quantum computers will require modular architectures that allow physical resources to be localized in easy-to-manage packages. In this work we examine the impact of different graph structures on the preparation of entangled states. We begin by explaining a formal framework, the hierarchical product, in which modular graphs can be easily constructed. This framework naturally leads us to suggest a class of graphs, which we dub hierarchies. We argue that such graphs have favorable properties for quantum information processing, such as a small diameter and small total edge weight, and use the concept of Pareto efficiency to identify promising quantum graph architectures. We present numerical and analytical results on the speed at which large entangled states can be created on nearest-neighbor grids and hierarchy graphs. We also present a scheme for performing circuit placement-the translation from circuit diagrams to machine qubits-on quantum systems whose connectivity is described by hierarchies.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.98.062328}, author = {Bapat, Aniruddha and Eldredge, Zachary and Garrison, James R. and Deshpande, Abhinav and Chong, Frederic T. and Gorshkov, Alexey V.} } @article { ISI:000414365000002, title = {Development of a new UHV/XHV pressure standard (cold atom vacuum standard)}, journal = {METROLOGIA}, volume = {54}, number = {6}, year = {2017}, month = {DEC}, pages = {S125-S132}, issn = {0026-1394}, doi = {10.1088/1681-7575/aa8a7b}, author = {Scherschligt, Julia and Fedchak, James A. and Barker, Daniel S. and Eckel, Stephen and Klimov, Nikolai and Makrides, Constantinos and Tiesinga, Eite} } @article { ISI:000407000100003, title = {Dynamically induced robust phonon transport and chiral cooling in an optomechanical system}, journal = {NATURE COMMUNICATIONS}, volume = {8}, year = {2017}, month = {AUG 7}, issn = {2041-1723}, doi = {10.1038/s41467-017-00247-7}, author = {Kim, Seunghwi and Xu, Xunnong and Taylor, Jacob M. and Bahl, Gaurav} } @article { ISI:000406665400001, title = {Entanglement Area Laws for Long-Range Interacting Systems}, journal = {PHYSICAL REVIEW LETTERS}, volume = {119}, number = {5}, year = {2017}, month = {JUL 31}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.119.050501}, author = {Gong, Zhe-Xuan and Foss-Feig, Michael and Brandao, Fernando G. S. L. and Gorshkov, Alexey V.} } @article { ISI:000413668800012, title = {Evidence for magnetic Weyl fermions in a correlated metal}, journal = {NATURE MATERIALS}, volume = {16}, number = {11}, year = {2017}, month = {NOV}, pages = {1090+}, issn = {1476-1122}, doi = {10.1038/NMAT4987}, author = {Kuroda, K. and Tomita, T. and Suzuki, M. -T. and Bareille, C. and Nugroho, A. A. and Goswami, P. and Ochi, M. and Ikhlas, M. and Nakayama, M. and Akebi, S. and Noguchi, R. and Ishii, R. and Inami, N. and Ono, K. and Kumigashira, H. and Varykhalov, A. and Muro, T. and Koretsune, T. and Arita, R. and Shin, S. and Kondo, Takeshi and Nakatsuji, S.} } @article { ISI:000411592600023, title = {Experimental phase diagram of zero-bias conductance peaks in superconductor/semiconductor nanowire devices}, journal = {SCIENCE ADVANCES}, volume = {3}, number = {9}, year = {2017}, month = {SEP}, issn = {2375-2548}, doi = {10.1126/sciadv.1701476}, author = {Chen, Jun and Yu, Peng and Stenger, John and Hocevar, Moira and Car, Diana and Plissard, Sebastien R. and Bakkers, Erik P. A. M. and Stanescu, Tudor D. and Frolov, Sergey M.} } @article { ISI:000412979000001, title = {Experimental Study of Optimal Measurements for Quantum State Tomography}, journal = {PHYSICAL REVIEW LETTERS}, volume = {119}, number = {15}, year = {2017}, month = {OCT 13}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.119.150401}, author = {Sosa-Martinez, H. and Lysne, N. K. and Baldwin, C. H. and Kalev, A. and Deutsch, I. H. and Jessen, P. S.} } @article { ISI:000412061700002, title = {Extracting Entanglement Geometry from Quantum States}, journal = {PHYSICAL REVIEW LETTERS}, volume = {119}, number = {14}, year = {2017}, month = {OCT 2}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.119.140502}, author = {Hyatt, Katharine and Garrison, James R. and Bauer, Bela} } @article { ISI:000415568700001, title = {Fast pulse sequences for dynamically corrected gates in singlet-triplet qubits}, journal = {PHYSICAL REVIEW B}, volume = {96}, number = {19}, year = {2017}, month = {NOV 17}, issn = {2469-9950}, doi = {10.1103/PhysRevB.96.195424}, author = {Throckmorton, Robert E. and Zhang, Chengxian and Yang, Xu-Chen and Wang, Xin and Barnes, Edwin and S. Das Sarma} } @article {7741, title = {Fault-tolerant quantum error detection}, journal = {Science Advances}, volume = {3}, year = {2017}, abstract = {Quantum computers will eventually reach a size at which quantum error correction becomes imperative. Quantum information can be protected from qubit imperfections and flawed control operations by encoding a single logical qubit in multiple physical qubits. This redundancy allows the extraction of error syndromes and the subsequent detection or correction of errors without destroying the logical state itself through direct measurement. We show the encoding and syndrome measurement of a fault-tolerantly prepared logical qubit via an error detection protocol on four physical qubits, represented by trapped atomic ions. This demonstrates the robustness of a logical qubit to imperfections in the very operations used to encode it. The advantage persists in the face of large added error rates and experimental calibration errors.

}, doi = {10.1126/sciadv.1701074}, url = {http://advances.sciencemag.org/content/3/10/e1701074}, author = {Linke, Norbert M. and Gutierrez, Mauricio and Landsman, Kevin A. and Figgatt, Caroline and Debnath, Shantanu and Brown, Kenneth R. and Monroe, Christopher} } @article { ISI:000406382800003, title = {Methods, analysis, and the treatment of systematic errors for the electron electric dipole moment search in thorium monoxide}, journal = {NEW JOURNAL OF PHYSICS}, volume = {19}, year = {2017}, month = {JUL 25}, issn = {1367-2630}, doi = {10.1088/1367-2630/aa708e}, author = {Baron, J. and Campbell, W. C. and DeMille, D. and Doyle, J. M. and Gabrielse, G. and Gurevich, Y. V. and Hess, P. W. and Hutzler, N. R. and Kirilov, E. and Kozyryev, I. and O{\textquoteright}Leary, B. R. and Panda, C. D. and Parsons, M. F. and Spaun, B. and Vutha, A. C. and West, A. D. and West, E. P. and ACME Collaboration} } @article {6496, title = {Modal interference in optical nanofibers for sub-Angstrom radius sensitivity}, journal = {Optica}, volume = {4}, year = {2017}, month = {Jan}, pages = {157{\textendash}162}, abstract = {Optical nanofibers (ONFs) of sub-wavelength dimensions confine light in modes with a strong evanescent field that can trap, probe, and manipulate nearby quantum systems. To measure the evanescent field and propagating modes and to optimize ONF performance, a surface probe is desirable during fabrication. We demonstrate a nondestructive near-field measurement of light propagation in ONFs by sampling the local evanescent field with a microfiber. This approach reveals the behavior of all propagating modes, and because the modal beat lengths in cylindrical waveguides depend strongly on the radius, it simultaneously provides exquisite sensitivity to the ONF radius. We show that our measured spatial frequencies provide a map of the average ONF radius (over a 600\&\#x00A0;\&\#x03BC;m window) along the 10\&\#x00A0;mm ONF waist with a 40\&\#x00A0;pm resolution and a high signal-to-noise ratio. The measurements agree with scanning electron microscopy (SEM) to within SEM instrument resolutions. This fast method is immune to polarization, intrinsic birefringence, mechanical vibrations, and scattered light and provides a set of constraints to protect from systematic errors in the measurements.

}, keywords = {Fiber characterization, Fiber optics, Nanophotonics and photonic crystals}, doi = {https://doi.org/10.1364/OPTICA.4.000157}, url = {http://www.osapublishing.org/optica/abstract.cfm?URI=optica-4-1-157}, author = {Fredrik K. Fatemi and Jonathan E. Hoffman and Pablo Solano and Eliot F. Fenton and Guy Beadie and Steven L. Rolston and Luis A. Orozco} } @article { ISI:000413927000009, title = {Non-thermalization in trapped atomic ion spin chains}, journal = {PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES}, volume = {375}, number = {2108}, year = {2017}, month = {DEC 13}, issn = {1364-503X}, doi = {10.1098/rsta.2017.0107}, author = {Hess, P. W. and Becker, P. and Kaplan, H. B. and Kyprianidis, A. and Lee, A. C. and Neyenhuis, B. and Pagano, G. and Richerme, P. and Senko, C. and Smith, J. and Tan, W. L. and Zhang, J. and Monroe, C.} } @article {6701, title = {Observation of a discrete time crystal}, journal = {Nature}, volume = {543}, year = {2017}, month = {03/2017}, pages = {217-220}, chapter = {217}, keywords = {ions, many-body localization, time crystal}, doi = {10.1038/nature21413}, author = {J Zhang and P W. Hess and A Kyprianidis and P Becker and A Lee and J Smith and G Pagano and I.-D Potirniche and A C. Potter and A Vishwanath and N Y. Yao and C Monroe} } @article {7821, title = {Observation of a many-body dynamical phase transition with a 53-qubit quantum simulator}, journal = {Nature}, volume = {551}, year = {2017}, chapter = {601}, author = {J Zhang and G Pagano and P. W. Hess and A Kyprianidis and P. Becker and H. Kaplan and A. V. Gorshkov and Gong, Z-X and Christopher Monroe} } @article {ISI:000396518400037, title = {Quantum frequency bridge: high-accuracy characterization of a nearly-noiseless parametric frequency converter}, journal = {OPTICS EXPRESS}, volume = {25}, number = {2}, year = {2017}, month = {JAN 23}, pages = {907-917}, abstract = {We demonstrate an efficient and inherently ultra-low noise frequency conversion via a parametric sum frequency generation. Due to the wide separation between the input and pump frequencies and the low pump frequency relative to the input photons, the upconversion results in only approximate to 100 background photons per hour. To measure such a low rate, we introduced a dark count reduction algorithm for an optical transition edge sensor. (C) 2017 Optical Society of America}, issn = {1094-4087}, doi = {10.1364/OE.25.000907}, author = {Burenkov, Ivan A. and Gerrits, Thomas and Lita, Adriana and Nam, Sae Woo and Shalm, L. Krister and Polyakov, Sergey V.} } @article { ISI:000404365400001, title = {Resilience of the quantum Rabi model in circuit QED}, journal = {JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL}, volume = {50}, number = {29}, year = {2017}, month = {JUL 21}, issn = {1751-8113}, doi = {10.1088/1751-8121/aa6fbc}, author = {Manucharyan, Vladimir E. and Baksic, Alexandre and Ciuti, Cristiano} } @article { ISI:000414951500015, title = {Spontaneous avalanche dephasing in large Rydberg ensembles}, journal = {PHYSICAL REVIEW A}, volume = {96}, number = {5}, year = {2017}, month = {NOV 13}, issn = {2469-9926}, doi = {10.1103/PhysRevA.96.053409}, author = {Boulier, T. and Magnan, E. and Bracamontes, C. and Maslek, J. and Goldschmidt, E. A. and Young, J. T. and Gorshkov, A. V. and Rolston, S. L. and Porto, J. V.} } @article {7871, title = {Super-radiance reveals infinite-range dipole interactions through a nanofiber}, journal = {Nature Communications}, volume = {8}, year = {2017}, pages = {1857}, abstract = {Atoms interact with each other through the electromagnetic field, creating collective states that can radiate faster or slower than a single atom, i.e., super- and sub-radiance. When the field is confined to one dimension it enables infinite-range atom{\textendash}atom interactions. Here we present the first report of infinite-range interactions between macroscopically separated atomic dipoles mediated by an optical waveguide. We use cold 87Rb atoms in the vicinity of a single-mode optical nanofiber (ONF) that coherently exchange evanescently coupled photons through the ONF mode. In particular, we observe super-radiance of a few atoms separated by hundreds of resonant wavelengths. The same platform allows us to measure sub-radiance, a rarely observed effect, presenting a unique tool for quantum optics. This result constitutes a proof of principle for collective behavior of macroscopically delocalized atomic states, a crucial element for new proposals in quantum information and many-body physics.

}, issn = {2041-1723}, doi = {10.1038/s41467-017-01994-3}, url = {https://doi.org/10.1038/s41467-017-01994-3}, author = {Solano, P and Barberis-Blostein, P and Fatemi, F K and Orozco, L A and Rolston, S L} } @article {4380, title = {Anomalous broadening in driven dissipative Rydberg systems}, journal = {Phys. Rev. Lett.}, volume = {116}, year = {2016}, month = {03/2016}, pages = {113001}, abstract = {We observe interaction-induced broadening of the two-photon 5s-18s transition in 87Rb atoms trapped in a 3D optical lattice. The measured linewidth increases by nearly two orders of magnitude with increasing atomic density and excitation strength, with corresponding suppression of resonant scattering and enhancement of off-resonant scattering. We attribute the increased linewidth to resonant dipole-dipole interactions of 18s atoms with blackbody induced population in nearby np states. Over a range of initial atomic densities and excitation strengths, the transition width is described by a single function of the steady-state density of Rydberg atoms, and the observed resonant excitation rate corresponds to that of a two-level system with the measured, rather than natural, linewidth. The broadening mechanism observed here is likely to have negative implications for many proposals with coherently interacting Rydberg atoms.

}, doi = {10.1103/PhysRevLett.116.113001}, author = {Goldschmidt, E A and Boulier, T and Brown, R C and Koller, S B and Young, J T and Gorshkov, A V and Rolston, S L and Porto, J V} } @article { ISI:000382008100013, title = {Charge 2e/3 Superconductivity and Topological Degeneracies without Localized Zero Modes in Bilayer Fractional Quantum Hall States}, journal = {PHYSICAL REVIEW LETTERS}, volume = {117}, number = {9}, year = {2016}, month = {AUG 24}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.117.096803}, author = {Barkeshli, Maissam} } @article {ISI:000392283300002, title = {Co-designing a scalable quantum computer with trapped atomic ions}, journal = {NPJ QUANTUM INFORMATION}, volume = {2}, year = {2016}, month = {NOV 8}, pages = {16034}, abstract = {The first generation of quantum computers are on the horizon, fabricated from quantum hardware platforms that may soon be able to tackle certain tasks that cannot be performed or modelled with conventional computers. These quantum devices will not likely be universal or fully programmable, but special-purpose processors whose hardware will be tightly co-designed with particular target applications. Trapped atomic ions are a leading platform for first-generation quantum computers, but they are also fundamentally scalable to more powerful general purpose devices in future generations. This is because trapped ion qubits are atomic clock standards that can be made identical to a part in 1015, and their quantum circuit connectivity can be reconfigured through the use of external fields, without modifying the arrangement or architecture of the qubits themselves. In this forwardlooking overview, we show how a modular quantum computer with thousands or more qubits can be engineered from ion crystals, and how the linkage between ion trap qubits might be tailored to a variety of applications and quantum-computing protocols.}, issn = {2056-6387}, doi = {10.1038/npjqi.2016.34}, author = {Brown, Kenneth R. and Kim, Jungsang and Monroe, Christopher} } @article { ISI:000376250800002, title = {Dirty Weyl semimetals: Stability, phase transition, and quantum criticality}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {20}, year = {2016}, month = {MAY 17}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.201302}, author = {Bera, Soumya and Sau, Jay D. and Roy, Bitan} } @article { ISI:000372799400003, title = {Drumhead surface states and topological nodal-line fermions in TlTaSe2}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {12}, year = {2016}, month = {MAR 28}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.121113}, author = {Bian, Guang and Chang, Tay-Rong and Zheng, Hao and Velury, Saavanth and Xu, Su-Yang and Neupert, Titus and Chiu, Ching-Kai and Huang, Shin-Ming and Sanchez, Daniel S. and Belopolski, Ilya and Alidoust, Nasser and Chen, Peng-Jen and Chang, Guoqing and Bansil, Arun and Jeng, Horng-Tay and Lin, Hsin and Hasan, M. Zahid} } @article { ISI:000368483600011, title = {Effects of nonequilibrium quasiparticles in a thin-film superconducting microwave resonator under optical illumination}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {2}, year = {2016}, month = {JAN 19}, pages = {024514}, issn = {1098-0121}, doi = {10.1103/PhysRevB.93.024514}, author = {Budoyo, R. P. and Hertzberg, J. B. and Ballard, C. J. and Voigt, K. D. and Kim, Z. and Anderson, J. R. and Lobb, C. J. and Wellstood, F. C.} } @article { ISI:000372413000004, title = {Filter function formalism beyond pure dephasing and non-Markovian noise in singlet-triplet qubits}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {12}, year = {2016}, month = {MAR 16}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.121407}, author = {Barnes, Edwin and Rudner, Mark S. and Martins, Frederico and Malinowski, Filip K. and Marcus, Charles M. and Kuemmeth, Ferdinand} } @article { ISI:000373117500001, title = {Interplanar coupling-dependent magnetoresistivity in high-purity layered metals}, journal = {NATURE COMMUNICATIONS}, volume = {7}, year = {2016}, month = {MAR}, issn = {2041-1723}, doi = {10.1038/ncomms10903}, author = {Kikugawa, N. and Goswami, P. and Kiswandhi, A. and Choi, E. S. and Graf, D. and Baumbach, R. E. and Brooks, J. S. and Sugii, K. and Iida, Y. and Nishio, M. and Uji, S. and Terashima, T. and Rourke, P. M. C. and Hussey, N. E. and Takatsu, H. and Yonezawa, S. and Maeno, Y. and Balicas, L.} } @article {ISI:000399139100002, title = {Interrupted orbital motion in density-wave systems}, journal = {PHYSICAL REVIEW B}, volume = {94}, number = {20}, year = {2016}, month = {NOV 2}, abstract = {In conventional metals, electronic transport in a magnetic field is characterized by the motion of electrons along orbits on the Fermi surface, which usually causes an increase in the resistivity through averaging over velocities. Here, we show that large deviations from this behavior can arise in density-wave systems close to their ordering temperature. Specifically, enhanced scattering off collective fluctuations can lead to a change of direction of the orbital motion on reconstructed pockets. In weak magnetic fields, this leads to linear magnetoconductivity, the sign of which depends on the electric-field direction. At a critical magnetic field, the conductivity crosses zero for certain directions, signifying a thermodynamic instability of the density-wave state.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.94.205103}, author = {Breitkreiz, Maxim and Brydon, P. M. R. and Timm, Carsten} } @article {ISI:000383412100015, title = {Nanostructure-Induced Distortion in Single-Emitter Microscopy}, journal = {NANO LETTERS}, volume = {16}, number = {9}, year = {2016}, month = {SEP}, pages = {5415-5419}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.6b01708}, author = {Lim, Kangmook and Ropp, Chad and Barik, Sabyasachi and Fourkas, John and Shapiro, Benjamin and Waks, Edo} } @article { ISI:000372432300003, title = {Noise Suppression Using Symmetric Exchange Gates in Spin Qubits}, journal = {PHYSICAL REVIEW LETTERS}, volume = {116}, number = {11}, year = {2016}, month = {MAR 16}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.116.116801}, author = {Martins, Frederico and Malinowski, Filip K. and Nissen, Peter D. and Barnes, Edwin and Fallahi, Saeed and Gardner, Geoffrey C. and Manfra, Michael J. and Marcus, Charles M. and Kuemmeth, Ferdinand} } @article { ISI:000370245900009, title = {Noise-induced collective quantum state preservation in spin qubit arrays}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {8}, year = {2016}, month = {FEB 16}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.085420}, author = {Barnes, Edwin and Deng, Dong-Ling and Throckmorton, Robert E. and Wu, Yang-Le and S. Das Sarma} } @article {14296, title = {Nonlinear looped band structure of Bose-Einstein condensates in an optical lattice}, journal = {Phys. Rev. A}, volume = {94}, year = {2016}, pages = {063634}, author = {Koller, Silvio B and Goldschmidt, Elizabeth A and Brown, Roger C and Wyllie, Robert and Wilson, Ryan W and Porto, J V} } @article { ISI:000374964400012, title = {Pairing of j=3/2 Fermions in Half-Heusler Superconductors}, journal = {PHYSICAL REVIEW LETTERS}, volume = {116}, number = {17}, year = {2016}, month = {APR 27}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.116.177001}, author = {Brydon, P. M. R. and Wang, Limin and Weinert, M. and Agterberg, D. F.} } @article {ISI:000374560300010, title = {Projected Dipole Moments of Individual Two-Level Defects Extracted Using Circuit Quantum Electrodynamics}, journal = {PHYSICAL REVIEW LETTERS}, volume = {116}, number = {16}, year = {2016}, month = {APR 22}, pages = {167002}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.116.167002}, author = {Sarabi, B. and Ramanayaka, A. N. and Burin, A. L. and Wellstood, F. C. and Osborn, K. D.} } @article {ISI:000383849400001, title = {Quantum-Enhanced Machine Learning}, journal = {PHYSICAL REVIEW LETTERS}, volume = {117}, number = {13}, year = {2016}, month = {SEP 20}, pages = {130501}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.117.130501}, author = {Dunjko, Vedran and Taylor, Jacob M. and Briegel, Hans J.} } @article {ISI:000375524900002, title = {Realizing exactly solvable SU(N) magnets with thermal atoms}, journal = {PHYSICAL REVIEW A}, volume = {93}, number = {5}, year = {2016}, month = {MAY 6}, pages = {051601}, issn = {2469-9926}, doi = {10.1103/PhysRevA.93.051601}, author = {Beverland, Michael E. and Alagic, Gorjan and Martin, Michael J. and Koller, Andrew P. and Rey, Ana M. and Gorshkov, Alexey V.} } @article { ISI:000376242200008, title = {Three-photon process for producing a degenerate gas of metastable alkaline-earth-metal atoms}, journal = {PHYSICAL REVIEW A}, volume = {93}, number = {5}, year = {2016}, month = {MAY 18}, pages = {053417}, issn = {2469-9926}, doi = {10.1103/PhysRevA.93.053417}, author = {Barker, D. S. and Pisenti, N. C. and Reschovsky, B. J. and Campbell, G. K.} } @article {ISI:000388016200001, title = {Two-dimensionally confined topological edge states in photonic crystals}, journal = {NEW JOURNAL OF PHYSICS}, volume = {18}, year = {2016}, month = {NOV 7}, pages = {113013}, abstract = {We present an all-dielectric photonic crystal structure that supports two-dimensionally confined helical topological edge states. The topological properties of the system are controlled by the crystal parameters. An interface between two regions of differing band topologies gives rise to topological edge states confined in a dielectric slab that propagate around sharp corners without backscattering. Three-dimensional finite-difference time-domain calculations show these edges to be confined in the out-of-plane direction by total internal reflection. Such nanoscale photonic crystal architectures could enable strong interactions between photonic edge states and quantum emitters.}, issn = {1367-2630}, doi = {10.1088/1367-2630/18/11/113013}, author = {Barik, Sabyasachi and Miyake, Hirokazu and DeGottardi, Wade and Waks, Edo and Hafezi, Mohammad} } @article {ISI:000392096800044, title = {An ultra-low noise, high-voltage piezo-driver}, journal = {REVIEW OF SCIENTIFIC INSTRUMENTS}, volume = {87}, number = {12}, year = {2016}, month = {DEC}, pages = {124702}, abstract = {We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low-current applications. The architecture uses a flyback switching regulator to generate up to 250 V in our current design, with an output of 1 kV or more possible with small modifications. A high slew-rate op-amp suppresses the residual switching noise, yielding a total root-mean-square noise of approximate to 100 mu V (1 Hz-100 kHz). A low-voltage (+/- 10 V), high bandwidth signal can be summed with unity gain directly onto the output, making the driver well-suited for closed-loop feedback applications. Digital control enables both repeatable setpoints and sophisticated control logic, and the circuit consumes less than 150 mA at +/- 15 V.}, issn = {0034-6748}, doi = {10.1063/1.4969059}, author = {Pisenti, N. C. and Restelli, A. and Reschovsky, B. J. and Barker, D. S. and Campbell, G. K.} } @article { ISI:000357261300002, title = {Abelian and non-Abelian states in nu=2/3 bilayer fractional quantum Hall systems}, journal = {PHYSICAL REVIEW B}, volume = {92}, number = {3}, year = {2015}, month = {JUL 2}, issn = {1098-0121}, doi = {10.1103/PhysRevB.92.035103}, author = {Peterson, Michael R. and Wu, Yang-Le and Cheng, Meng and Barkeshli, Maissam and Wang, Zhenghan and S. Das Sarma} } @article { ISI:000352470000003, title = {Analytical approach to swift nonleaky entangling gates in superconducting qubits}, journal = {PHYSICAL REVIEW B}, volume = {91}, number = {16}, year = {2015}, month = {APR 9}, issn = {1098-0121}, doi = {10.1103/PhysRevB.91.161405}, author = {Economou, Sophia E. and Barnes, Edwin} } @article { ISI:000353969200003, title = {Ancillary Qubit Spectroscopy of Vacua in Cavity and Circuit Quantum Electrodynamics}, journal = {PHYSICAL REVIEW LETTERS}, volume = {114}, number = {18}, year = {2015}, month = {MAY 6}, pages = {183601}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.114.183601}, author = {Lolli, Jared and Baksic, Alexandre and Nagy, David and Manucharyan, Vladimir E. and Ciuti, Cristiano} } @article { ISI:000360650200001, title = {Approaching the quantum limit for nanoplasmonics}, journal = {JOURNAL OF MATERIALS RESEARCH}, volume = {30}, number = {16}, year = {2015}, month = {AUG 28}, pages = {2389-2399}, issn = {0884-2914}, doi = {10.1557/jmr.2015.232}, author = {Townsend, Emily and Debrecht, Alex and Bryant, Garnett W.} } @article { ISI:000360959800006, title = {Bilayer fractional quantum Hall states with dipoles}, journal = {PHYSICAL REVIEW A}, volume = {92}, number = {3}, year = {2015}, month = {SEP 10}, pages = {033609}, issn = {1050-2947}, doi = {10.1103/PhysRevA.92.033609}, author = {Yao, N. Y. and Bennett, S. D. and Laumann, C. R. and Lev, B. L. and Gorshkov, A. V.} } @article { ISI:000361376200011, title = {Bound States of a Ferromagnetic Wire in a Superconductor}, journal = {PHYSICAL REVIEW LETTERS}, volume = {115}, number = {12}, year = {2015}, month = {SEP 18}, pages = {127003}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.115.127003}, author = {Sau, Jay D. and Brydon, P. M. R.} } @article { ISI:000353839100036, title = {Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state}, journal = {APPLIED PHYSICS LETTERS}, volume = {106}, number = {17}, year = {2015}, month = {APR 27}, issn = {0003-6951}, doi = {10.1063/1.4918775}, author = {Sarabi, B. and Ramanayaka, A. N. and Burin, A. L. and Wellstood, F. C. and Osborn, K. D.} } @article { ISI:000365773300003, title = {Chirality-protected Majorana zero modes at the gapless edge of Abelian quantum Hall states}, journal = {PHYSICAL REVIEW B}, volume = {92}, number = {19}, year = {2015}, month = {NOV 30}, issn = {1098-0121}, doi = {10.1103/PhysRevB.92.195152}, author = {Cano, Jennifer and Cheng, Meng and Barkeshli, Maissam and Clarke, David J. and Nayak, Chetan} } @conference { ISI:000353892600004, title = {Coherent control of energy transfer in a quantum dot strongly coupled to a photonic crystal molecule}, booktitle = {ADVANCES IN PHOTONICS OF QUANTUM COMPUTING, MEMORY, AND COMMUNICATION VIII}, series = {Proceedings of SPIE}, volume = {9377}, year = {2015}, note = {Conference on Advances in Photonics of Quantum Computing, Memory, and Communication VIII, San Francisco, CA, FEB 10-12, 2015}, isbn = {978-1-62841-467-7}, issn = {0277-786X}, doi = {10.1117/12.2078199}, author = {Cai, Tao and Bose, Ranojoy and Choudhury, Kaushik Roy and Solomon, Glenn S. and Waks, Edo}, editor = {Hasan, ZU and Hemmer, PR and Lee, H and Migdall, AL} } @article { ISI:000356473300003, title = {Conductance spectroscopy of topological superconductor wire junctions}, journal = {PHYSICAL REVIEW B}, volume = {91}, number = {21}, year = {2015}, month = {JUN 18}, pages = {214513}, issn = {1098-0121}, doi = {10.1103/PhysRevB.91.214513}, author = {Setiawan, F. and Brydon, P. M. R. and Sau, Jay D. and S. Das Sarma} } @article {3041, title = {Controlling Neutron Orbital Angular Momentum}, journal = {Nature}, volume = {525}, year = {2015}, month = {September 2015}, chapter = {504}, doi = {10.1038/nature15265}, url = {http://www.nature.com/nature/journal/v525/n7570/full/nature15265.html}, author = {Charles W. Clark and Roman Barankov and Michael G. Huber and Muhammad Arif and David G. Cory and Dmitry A. Pushin} } @article { ISI:000361316500008, title = {Coulomb Bound States of Strongly Interacting Photons}, journal = {PHYSICAL REVIEW LETTERS}, volume = {115}, number = {12}, year = {2015}, month = {SEP 16}, pages = {123601}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.115.123601}, author = {Maghrebi, M. F. and Gullans, M. J. and Bienias, P. and Choi, S. and Martin, I. and Firstenberg, O. and Lukin, M. D. and Buechler, H. P. and Gorshkov, A. V.} } @article { ISI:000367236600015, title = {Directly probing the Chern number of the Haldane model in optical lattices}, journal = {JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS}, volume = {32}, number = {12}, year = {2015}, month = {DEC 1}, pages = {2500-2506}, issn = {0740-3224}, doi = {10.1364/JOSAB.32.002500}, author = {Liu, Rui-Bin and Deng, Dong-Ling and Zhang, Dan-Wei and Zhu, Shi-Liang} } @article { ISI:000349786400007, title = {Effects of a tilted magnetic field in a Dirac double layer}, journal = {PHYSICAL REVIEW B}, volume = {91}, number = {8}, year = {2015}, month = {FEB 20}, issn = {1098-0121}, doi = {10.1103/PhysRevB.91.085418}, author = {Pershoguba, Sergey S. and Abergel, D. S. L. and Yakovenko, Victor M. and Balatsky, A. V.} } @article { ISI:000367373700012, title = {Efimov correlations in strongly interacting Bose gases}, journal = {PHYSICAL REVIEW A}, volume = {92}, number = {6}, year = {2015}, month = {DEC 30}, issn = {1050-2947}, doi = {10.1103/PhysRevA.92.062716}, author = {Barth, Marcus and Hofmann, Johannes} } @article { ISI:000366339600012, title = {Electronic Transport and Possible Superconductivity at Van Hove Singularities in Carbon Nanotubes}, journal = {NANO LETTERS}, volume = {15}, number = {12}, year = {2015}, month = {DEC}, pages = {7859-7866}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.5b02564}, author = {Yang, Y. and Fedorov, G. and Shafranjuk, S. E. and Klapwijk, T. M. and Cooper, B. K. and Lewis, R. M. and Lobb, C. J. and Barbara, P.} } @article { ISI:000365002800001, title = {Emergence of Chaotic Scattering in Ultracold Er and Dy}, journal = {PHYSICAL REVIEW X}, volume = {5}, number = {4}, year = {2015}, month = {NOV 19}, issn = {2160-3308}, doi = {10.1103/PhysRevX.5.041029}, author = {Maier, T. and Kadau, H. and Schmitt, M. and Wenzel, M. and Ferrier-Barbut, I. and Pfau, T. and Frisch, A. and Baier, S. and Aikawa, K. and Chomaz, L. and Mark, M. J. and Ferlaino, F. and Makrides, C. and Tiesinga, E. and Petrov, A. and Kotochigova, S.} } @article { ISI:000363509700004, title = {Enhanced magnetic trap loading for atomic strontium}, journal = {PHYSICAL REVIEW A}, volume = {92}, number = {4}, year = {2015}, month = {OCT 26}, pages = {043418}, issn = {1050-2947}, doi = {10.1103/PhysRevA.92.043418}, author = {Barker, D. S. and Reschovsky, B. J. and Pisenti, N. C. and Campbell, G. K.} } @article { ISI:000358928600002, title = {Gauge matters: observing the vortex-nucleation transition in a Bose condensate}, journal = {NEW JOURNAL OF PHYSICS}, volume = {17}, year = {2015}, month = {JUN 18}, pages = {065016}, issn = {1367-2630}, doi = {10.1088/1367-2630/17/6/065016}, author = {LeBlanc, L. J. and Jimenez-Garcia, K. and Williams, R. A. and Beeler, M. C. and Phillips, W. D. and Ian B Spielman} } @article { ISI:000360894300012, title = {Gigantic Surface Lifetime of an Intrinsic Topological Insulator}, journal = {PHYSICAL REVIEW LETTERS}, volume = {115}, number = {11}, year = {2015}, month = {SEP 9}, pages = {116801}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.115.116801}, author = {Neupane, Madhab and Xu, Su-Yang and Ishida, Yukiaki and Jia, Shuang and Fregoso, Benjamin M. and Liu, Chang and Belopolski, Ilya and Bian, Guang and Alidoust, Nasser and Durakiewicz, Tomasz and Victor M Galitski and Shin, Shik and Cava, Robert J. and Hasan, M. Zahid} } @article { ISI:000358737200017, title = {Harnessing high-dimensional hyperentanglement through a biphoton frequency comb}, journal = {NATURE PHOTONICS}, volume = {9}, number = {8}, year = {2015}, month = {AUG}, pages = {536+}, issn = {1749-4885}, doi = {10.1038/NPHOTON.2015.110}, author = {Xie, Zhenda and Zhong, Tian and Shrestha, Sajan and Xu, XinAn and Liang, Junlin and Gong, Yan-Xiao and Bienfang, Joshua C. and Restelli, Alessandro and Shapiro, Jeffrey H. and Wong, Franco N. C. and Wong, Chee Wei} } @article { ISI:000348759300001, title = {Helical spin texture of surface states in topological superconductors}, journal = {NEW JOURNAL OF PHYSICS}, volume = {17}, year = {2015}, month = {JAN 15}, issn = {1367-2630}, doi = {10.1088/1367-2630/17/1/013016}, author = {Brydon, P. M. R. and Schnyder, Andreas P. and Timm, Carsten} } @article {3000, title = {Hyperfine Anomalies in Fr: Boundaries of the Spherical Single Particle Model}, journal = {Phys. Rev. Lett.}, volume = {115}, year = {2015}, month = {Jul}, pages = {042501}, doi = {10.1103/PhysRevLett.115.042501}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.115.042501}, author = {Zhang, J. and Tandecki, M. and Collister, R. and Aubin, S. and Behr, J. A. and Gomez, E. and Gwinner, G. and Orozco, L. A. and Pearson, M. R. and Sprouse, G. D.} } @article { ISI:000357487000006, title = {Interacting Dirac liquid in three-dimensional semimetals}, journal = {PHYSICAL REVIEW B}, volume = {92}, number = {4}, year = {2015}, month = {JUL 6}, issn = {1098-0121}, doi = {10.1103/PhysRevB.92.045104}, author = {Hofmann, Johannes and Barnes, Edwin and S. Das Sarma} } @article {2899, title = {Magic wavelengths for the 5s-18s transition in rubidium}, journal = {Phys. Rev. A}, volume = {91}, year = {2015}, month = {Mar}, pages = {032518}, doi = {10.1103/PhysRevA.91.032518}, url = {http://link.aps.org/doi/10.1103/PhysRevA.91.032518}, author = {Goldschmidt, E A and Norris, D G and Koller, S B and Wyllie, R and Brown, R C and Porto, J V and Safronova, U I and Safronova, M S} } @article {ISI:000350480100001, title = {Majorana fermions in ferromagnetic chains on the surface of bulk spin-orbit coupled s-wave superconductors}, journal = {SCIENTIFIC REPORTS}, volume = {5}, year = {2015}, month = {MAR 6}, pages = {8880}, issn = {2045-2322}, doi = {10.1038/srep08880}, author = {Hui, Hoi-Yin and Brydon, P. M. R. and Sau, Jay D. and Tewari, S. and S. Das Sarma} } @article { ISI:000360331300001, title = {Many-body effects and ultraviolet renormalization in three-dimensional Dirac materials}, journal = {PHYSICAL REVIEW B}, volume = {92}, number = {11}, year = {2015}, month = {SEP 1}, issn = {1098-0121}, doi = {10.1103/PhysRevB.92.115101}, author = {Throckmorton, Robert E. and Hofmann, Johannes and Barnes, Edwin and S. Das Sarma} } @article { ISI:000357636300003, title = {Matrix product state representation of non-Abelian quasiholes}, journal = {PHYSICAL REVIEW B}, volume = {92}, number = {4}, year = {2015}, month = {JUL 9}, issn = {1098-0121}, doi = {10.1103/PhysRevB.92.045109}, author = {Wu, Yang-Le and Estienne, B. and Regnault, N. and Bernevig, B. Andrei} } @article { ISI:000349814400017, title = {The Morphology of Narrow Gaps Modifies the Plasmonic Response}, journal = {ACS PHOTONICS}, volume = {2}, number = {2}, year = {2015}, month = {FEB}, pages = {295-305}, issn = {2330-4022}, doi = {10.1021/ph5004016}, author = {Esteban, Ruben and Aguirregabiria, Garikoitz and Borisov, Andrey G. and Wang, Yumin M. and Nordlander, Peter and Bryant, Garnett W. and Javier Aizpurua} } @article {ISI:000351362200012, title = {Movable Thin-Film Superconducting Resonator Coupled to a Tapered Optical Microfiber at 15 mK}, journal = {IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY}, volume = {25}, number = {3}, year = {2015}, month = {JUN}, pages = {1700305}, issn = {1051-8223}, doi = {10.1109/TASC.2014.2379628}, author = {Voigt, K. D. and Hertzberg, J. B. and Hoffman, J. E. and Grover, J. A. and Solano, P. and Budoyo, R. P. and Ballard, C. and Lee, J. and Anderson, J. R. and Lobb, C. J. and Orozco, L. A. and Rolston, S. L. and Wellstood, E. C.} } @article { ISI:000365771800007, title = {Nonlinear microwave photon occupancy of a driven resonator strongly coupled to a transmon qubit}, journal = {PHYSICAL REVIEW A}, volume = {92}, number = {6}, year = {2015}, month = {DEC 2}, issn = {1050-2947}, doi = {10.1103/PhysRevA.92.063801}, author = {Suri, B. and Keane, Z. K. and Bishop, Lev S. and Novikov, S. and Wellstood, F. C. and Palmer, B. S.} } @article { ISI:000360810200003, title = {On-chip silicon waveguide Bragg grating photonic temperature sensor}, journal = {OPTICS LETTERS}, volume = {40}, number = {17}, year = {2015}, month = {SEP 1}, pages = {3934-3936}, issn = {0146-9592}, doi = {10.1364/OL.40.003934}, author = {Klimov, Nikolai N. and Mittal, Sunil and Berger, Michaela and Ahmed, Zeeshan} } @article { ISI:000359938200016, title = {Optical Feshbach resonances: Field-dressed theory and comparison with experiments}, journal = {PHYSICAL REVIEW A}, volume = {92}, number = {2}, year = {2015}, month = {AUG 24}, issn = {1050-2947}, doi = {10.1103/PhysRevA.92.022709}, author = {Nicholson, T. L. and Blatt, S. and Bloom, B. J. and James R. Williams and Thomsen, J. W. and Ye, J. and Julienne, Paul S.} } @article {ISI:000346828000014, title = {Photon number resolution enables quantum receiver for realistic coherent optical communications}, journal = {NATURE PHOTONICS}, volume = {9}, number = {1}, year = {2015}, month = {JAN}, pages = {48-53}, abstract = {Quantum-enhanced measurements can provide information about the properties of a physical system with sensitivities beyond what is fundamentally possible with conventional technologies. However, this advantage can be achieved only if quantum measurement technologies are robust against losses and real-world imperfections, and can operate in regimes compatible with existing systems. Here, we demonstrate a quantum receiver for coherent communication, the performance of which not only surpasses the standard quantum limit, but does so for input powers extending to high mean photon numbers. This receiver uses adaptive measurements and photon number resolution to achieve high sensitivity and robustness against imperfections, and ultimately shows the greatest advantage over the standard quantum limit ever achieved by any quantum receiver at power levels compatible with state-of-the-art optical communication systems. Our demonstration shows that quantum measurements can provide real and practical advantages over conventional technologies for optical communications.}, issn = {1749-4885}, doi = {10.1038/NPHOTON.2014.280}, author = {Becerra, F. E. and Fan, J. and Migdall, A.} } @article { ISI:000352864700001, title = {Photon-efficient quantum key distribution using time-energy entanglement with high-dimensional encoding}, journal = {NEW JOURNAL OF PHYSICS}, volume = {17}, year = {2015}, month = {FEB 4}, issn = {1367-2630}, doi = {10.1088/1367-2630/17/2/022002}, author = {Zhong, Tian and Zhou, Hongchao and Horansky, Robert D. and Lee, Catherine and Verma, Varun B. and Lita, Adriana E. and Restelli, Alessandro and Bienfang, Joshua C. and Mirin, Richard P. and Gerrits, Thomas and Nam, Sae Woo and Marsili, Francesco and Shaw, Matthew D. and Zhang, Zheshen and Wang, Ligong and Englund, Dirk and Wornell, Gregory W. and Shapiro, Jeffrey H. and Wong, Franco N. C.} } @article {2887, title = {Rayleigh scattering in an optical nanofiber as a probe of higher-order mode propagation}, journal = {Optica}, volume = {2}, year = {2015}, pages = {416}, doi = {10.1364/OPTICA.2.000416}, url = {http://www.opticsinfobase.org/optica/abstract.cfm?uri=optica-2-5-416}, author = {Jonathan E Hoffman and Fredrik K Fatemi and Guy Beadie and Steven L Rolston and Luis A Orozco} } @article { ISI:000359102300002, title = {Robust quantum control using smooth pulses and topological winding}, journal = {SCIENTIFIC REPORTS}, volume = {5}, year = {2015}, month = {AUG 4}, issn = {2045-2322}, doi = {10.1038/srep12685}, author = {Barnes, Edwin and Wang, Xin and S. Das Sarma} } @article { ISI:000354965000008, title = {Scaling of fluctuations in a trapped binary condensate}, journal = {PHYSICAL REVIEW A}, volume = {91}, number = {5}, year = {2015}, month = {MAY 15}, issn = {1050-2947}, doi = {10.1103/PhysRevA.91.053613}, author = {Bisset, R. N. and Wilson, R. M. and Ticknor, C.} } @article { ISI:000366486600002, title = {Strong Loophole-Free Test of Local Realism}, journal = {PHYSICAL REVIEW LETTERS}, volume = {115}, number = {25}, year = {2015}, month = {DEC 16}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.115.250402}, author = {Shalm, Lynden K. and Meyer-Scott, Evan and Christensen, Bradley G. and Bierhorst, Peter and Wayne, Michael A. and Stevens, Martin J. and Gerrits, Thomas and Glancy, Scott and Hamel, Deny R. and Allman, Michael S. and Coakley, Kevin J. and Dyer, Shellee D. and Hodge, Carson and Lita, Adriana E. and Verma, Varun B. and Lambrocco, Camilla and Tortorici, Edward and Migdall, Alan L. and Zhang, Yanbao and Kumor, Daniel R. and Farr, William H. and Marsili, Francesco and Shaw, Matthew D. and Stern, Jeffrey A. and Abellan, Carlos and Amaya, Waldimar and Pruneri, Valerio and Jennewein, Thomas and Mitchell, Morgan W. and Kwiat, Paul G. and Bienfang, Joshua C. and Mirin, Richard P. and Knill, Emanuel and Nam, Sae Woo} } @article { ISI:000357263100001, title = {Substrate-induced Majorana renormalization in topological nanowires}, journal = {NEW JOURNAL OF PHYSICS}, volume = {17}, year = {2015}, month = {JUL 2}, pages = {075001}, issn = {1367-2630}, doi = {10.1088/1367-2630/17/7/075001}, author = {S. Das Sarma and Hui, Hoi-Yin and Brydon, P. M. R. and Sau, Jay D.} } @article { ISI:000354548200001, title = {Surface instability in nodal noncentrosymmetric superconductors}, journal = {PHYSICAL REVIEW B}, volume = {91}, number = {18}, year = {2015}, month = {MAY 13}, issn = {1098-0121}, doi = {10.1103/PhysRevB.91.180503}, author = {Timm, Carsten and Rex, Stefan and Brydon, P. M. R.} } @article { ISI:000353704100004, title = {Systematic evaluation of an atomic clock at 2 x 10 (-18) total uncertainty}, journal = {NATURE COMMUNICATIONS}, volume = {6}, year = {2015}, month = {APR}, issn = {2041-1723}, doi = {10.1038/ncomms7896}, author = {Nicholson, T. L. and S. L. Campbell and Hutson, R. B. and Marti, G. E. and Bloom, B. J. and McNally, R. L. and Zhang, W. and Barrett, M. D. and Safronova, M. S. and Strouse, G. F. and Tew, W. L. and Ye, J.} } @article { ISI:000355834800002, title = {Topological surface states in nodal superconductors}, journal = {JOURNAL OF PHYSICS-CONDENSED MATTER}, volume = {27}, number = {24}, year = {2015}, month = {JUN 24}, issn = {0953-8984}, doi = {10.1088/0953-8984/27/24/243201}, author = {Schnyder, Andreas P. and Brydon, Philip M. R.} } @article {ISI:000352302300005, title = {Topological Yu-Shiba-Rusinov chain from spin-orbit coupling}, journal = {PHYSICAL REVIEW B}, volume = {91}, number = {6}, year = {2015}, month = {FEB 17}, pages = {064505}, issn = {1098-0121}, doi = {10.1103/PhysRevB.91.064505}, author = {Brydon, P. M. R. and S. Das Sarma and Hui, Hoi-Yin and Sau, Jay D.} } @article {ISI:000353916300007, title = {Tunable Spin-Orbit Coupling via Strong Driving in Ultracold-Atom Systems}, journal = {PHYSICAL REVIEW LETTERS}, volume = {114}, number = {12}, year = {2015}, month = {MAR 24}, pages = {125301}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.114.125301}, author = {Jimenez-Garcia, K. and LeBlanc, L. J. and Williams, R. A. and Beeler, M. C. and Qu, C. and Gong, M. and Zhang, C. and Ian B Spielman} } @article {2905, title = {Two-dimensional superexchange-mediated magnetization dynamics in an optical lattice}, journal = {Science}, volume = {348}, year = {2015}, pages = {540}, doi = {10.1126/science.aaa1385}, url = {https://www.sciencemag.org/content/348/6234/540.short?related-urls=yes\&legid=sci;348/6234/540}, author = {Brown, R C and Wyllie, R and Koller, S B and Goldschmidt, E A and Foss-Feig, Michael and Porto, J V} } @article { ISI:000350552200018, title = {Afterpulse Reduction Through Prompt Quenching in Silicon Reach-Through Single-Photon Avalanche Diodes}, journal = {JOURNAL OF LIGHTWAVE TECHNOLOGY}, volume = {32}, number = {21}, year = {2014}, month = {NOV 1}, pages = {4097-4103}, issn = {0733-8724}, doi = {10.1109/JLT.2014.2346736}, author = {Wayne, Michael A. and Restelli, Alessandro and Bienfang, Joshua C. and Kwiat, Paul G.} } @article { ISI:000344840400014, title = {All-optical coherent control of vacuum Rabi oscillations}, journal = {NATURE PHOTONICS}, volume = {8}, number = {11}, year = {2014}, month = {NOV}, pages = {858-864}, issn = {1749-4885}, doi = {10.1038/NPHOTON.2014.224}, author = {Bose, Ranojoy and Cai, Tao and Choudhury, Kaushik Roy and Solomon, Glenn S. and Waks, Edo} } @article { ISI:000336746900010, title = {An Automated Approach to Map the History of Forest Disturbance from Insect Mortality and Harvest with Landsat Time-Series Data}, journal = {REMOTE SENSING}, volume = {6}, number = {4}, year = {2014}, month = {APR}, pages = {2782-2808}, issn = {2072-4292}, doi = {10.3390/rs6042782}, author = {Neigh, Christopher S. R. and Bolton, Douglas K. and Diabate, Mouhamad and Williams, Jennifer J. and Carvalhais, Nuno} } @article { ISI:000333920000014, title = {Beyond the Spin Model Approximation for Ramsey Spectroscopy}, journal = {PHYSICAL REVIEW LETTERS}, volume = {112}, number = {12}, year = {2014}, month = {MAR 26}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.112.123001}, author = {Koller, A. P. and Beverland, M. and Gorshkov, A. V. and Rey, A. M.} } @article { ISI:000342151500005, title = {Cross Modulation of Two Laser Beams at the Individual-Photon Level}, journal = {PHYSICAL REVIEW LETTERS}, volume = {113}, number = {11}, year = {2014}, month = {SEP 12}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.113.113603}, author = {Beck, Kristin M. and Chen, Wenlan and Lin, Qian and Gullans, Michael and Lukin, Mikhail D. and Vuletic, Vladan} } @article {2643, title = {Direct measurement of sub-wavelength interference using thermal light and photon-number-resolved detection}, journal = {Applied Physics Letters}, volume = {105}, year = {2014}, pages = {-}, doi = {10.1063/1.4895101}, url = {http://scitation.aip.org/content/aip/journal/apl/105/10/10.1063/1.4895101}, author = {Zhai, Yanhua and Becerra, Francisco E. and Jingyun Fan and Alan Migdall} } @article { ISI:000338653100001, title = {Effective field theory, three-loop perturbative expansion, and their experimental implications in graphene many-body effects}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {23}, year = {2014}, month = {JUN 25}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.235431}, author = {Barnes, Edwin and Hwang, E. H. and Throckmorton, R. E. and S. Das Sarma} } @article { ISI:000333694200003, title = {Effective-range approximations for resonant scattering of cold atoms}, journal = {PHYSICAL REVIEW A}, volume = {89}, number = {4}, year = {2014}, month = {APR 3}, issn = {1050-2947}, doi = {10.1103/PhysRevA.89.042701}, author = {Blackley, Caroline L. and Julienne, Paul S. and Hutson, Jeremy M.} } @article { ISI:000344903500011, title = {Gold Nanorods with Sub-Nanometer Separation using Cucurbit{[}n]uril for SERS Applications}, journal = {SMALL}, volume = {10}, number = {21}, year = {2014}, month = {NOV 12}, pages = {4298-4303}, issn = {1613-6810}, doi = {10.1002/smll.201401063}, author = {Jones, Samuel T. and Taylor, Richard W. and Esteban, Ruben and Abo-Hamed, Enass K. and Bomans, Paul H. H. and Sommerdijk, Nico A. J. M. and Javier Aizpurua and Baumberg, Jeremy J. and Scherman, Oren A.} } @article { ISI:000339998300001, title = {Helical order in one-dimensional magnetic atom chains and possible emergence of Majorana bound states}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {6}, year = {2014}, month = {AUG 4}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.060401}, author = {Kim, Younghyun and Cheng, Meng and Bauer, Bela and Lutchyn, Roman M. and S. Das Sarma} } @article { ISI:000345514700018, title = {High-resolution, vacuum-ultraviolet absorption spectrum of boron trifluoride}, journal = {JOURNAL OF CHEMICAL PHYSICS}, volume = {141}, number = {19}, year = {2014}, month = {NOV 21}, issn = {0021-9606}, doi = {10.1063/1.4901324}, author = {Hughes, Patrick P. and Beasten, Amy and McComb, Jacob C. and Coplan, Michael A. and Al-Sheikhly, Mohamad and Thompson, Alan K. and Vest, Robert E. and Sprague, Matthew K. and Irikura, Karl K. and Clark, Charles W.} } @article { ISI:000342130100002, title = {Interplay between Kondo and Majorana Interactions in Quantum Dots}, journal = {PHYSICAL REVIEW X}, volume = {4}, number = {3}, year = {2014}, month = {SEP 17}, issn = {2160-3308}, doi = {10.1103/PhysRevX.4.031051}, author = {Cheng, Meng and Becker, Michael and Bauer, Bela and Lutchyn, Roman M.} } @article { ISI:000345243400004, title = {Isotope shifts in francium isotopes Fr206-213 and Fr-221}, journal = {PHYSICAL REVIEW A}, volume = {90}, number = {5}, year = {2014}, month = {NOV 7}, issn = {1050-2947}, doi = {10.1103/PhysRevA.90.052502}, author = {Collister, R. and Gwinner, G. and Tandecki, M. and Behr, J. A. and Pearson, M. R. and Zhang, J. and Orozco, L. A. and Aubin, S. and Gomez, E. and FrPNC Collaboration} } @article { ISI:000343756200001, title = {Landau-Zener population control and dipole measurement of a two-level-system bath}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {10}, year = {2014}, month = {SEP 29}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.100201}, author = {Khalil, M. S. and Gladchenko, S. and Stoutimore, M. J. A. and Wellstood, F. C. and Burin, A. L. and Osborn, K. D.} } @article {2365, title = {Large-scale modular quantum-computer architecture with atomic memory and photonic interconnects}, journal = {Phys. Rev. A}, volume = {89}, year = {2014}, month = {Feb}, pages = {022317}, doi = {10.1103/PhysRevA.89.022317}, url = {http://link.aps.org/doi/10.1103/PhysRevA.89.022317}, author = {Christopher Monroe and Raussendorf, R. and Ruthven, A. and Brown, K. R. and P Maunz and L M Duan and Kim, J.} } @article { ISI:000342757000035, title = {Laser beam steering for GRACE Follow-On intersatellite interferometry}, journal = {OPTICS EXPRESS}, volume = {22}, number = {20}, year = {2014}, month = {OCT 6}, pages = {24117-24132}, issn = {1094-4087}, doi = {10.1364/OE.22.024117}, author = {Schuetze, Daniel and Stede, Gunnar and Mueller, Vitali and Gerberding, Oliver and Bandikova, Tamara and Sheard, Benjamin S. and Heinzel, Gerhard and Danzmann, Karsten} } @article { ISI:000342495700002, title = {Mass scaling and nonadiabatic effects in photoassociation spectroscopy of ultracold strontium atoms}, journal = {PHYSICAL REVIEW A}, volume = {90}, number = {3}, year = {2014}, month = {SEP 16}, issn = {1050-2947}, doi = {10.1103/PhysRevA.90.032713}, author = {Borkowski, Mateusz and Morzynski, Piotr and Ciurylo, Roman and Julienne, Paul S. and Yan, Mi and DeSalvo, Brian J. and Killian, T. C.} } @article { ISI:000341152100007, title = {Measuring Gaussian noise using a lock-in amplifier}, journal = {AMERICAN JOURNAL OF PHYSICS}, volume = {82}, number = {8}, year = {2014}, month = {AUG}, pages = {778-784}, issn = {0002-9505}, doi = {10.1119/1.4873694}, author = {Kouh, T. and Kemiktarak, U. and Basarir, O. and Lissandrello, C. and Ekinci, K. L.} } @article { ISI:000329984900016, title = {Noise kernel near the horizon of de Sitter space}, journal = {CLASSICAL AND QUANTUM GRAVITY}, volume = {31}, number = {2}, year = {2014}, month = {JAN 21}, issn = {0264-9381}, doi = {10.1088/0264-9381/31/2/025015}, author = {Bates, Jason D. and Cho, H. T. and Anderson, Paul R. and Bei-Lok Hu} } @article { ISI:000343304600003, title = {Noise-compensating pulses for electrostatically controlled silicon spin qubits}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {15}, year = {2014}, month = {OCT 14}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.155306}, author = {Wang, Xin and Calderon-Vargas, F. A. and Rana, Muhed S. and Kestner, J. P. and Barnes, Edwin and S. Das Sarma} } @article { ISI:000336436400013, title = {Nonequilibrium probe of paired electron pockets in the underdoped cuprates}, journal = {SOLID STATE COMMUNICATIONS}, volume = {189}, year = {2014}, month = {JUL}, pages = {63-67}, issn = {0038-1098}, doi = {10.1016/j.ssc.2014.03.015}, author = {Boyd, G. R. and Takei, S. and Victor M Galitski} } @article { ISI:000345422200008, title = {Odd-parity superconductivity from phonon-mediated pairing: Application to CuxBi2Se3}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {18}, year = {2014}, month = {NOV 14}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.184512}, author = {Brydon, P. M. R. and S. Das Sarma and Hui, Hoi-Yin and Sau, Jay D.} } @article { ISI:000345858500056, title = {Offline trapping of Fr-221 in a magneto-optical trap from implantation of an Ac-225 ion beam}, journal = {JOURNAL OF INSTRUMENTATION}, volume = {9}, year = {2014}, month = {OCT}, issn = {1748-0221}, doi = {10.1088/1748-0221/9/10/P10013}, author = {Tandeck, M. and Zhang, J. and Aubin, S. and Behr, J. A. and Collister, R. and Gomez, E. and Gwinner, G. and Heggen, H. and Lassen, J. and Orozco, L. A. and Pearson, M. R. and Raeder, S. and Teigelhoefer, A.} } @article { ISI:000332224400046, title = {Optical detection of radio waves through a nanomechanical transducer}, journal = {NATURE}, volume = {507}, number = {7490}, year = {2014}, month = {MAR 6}, pages = {81-85}, issn = {0028-0836}, doi = {10.1038/nature13029}, author = {Bagci, T. and Simonsen, A. and Schmid, S. and Villanueva, L. G. and Zeuthen, E. and J. Appel and Taylor, J. M. and Sorensen, A. and Usami, K. and Schliesser, A. and Polzik, E. S.} } @article {2396, title = {An optical lattice clock with accuracy and stability at the 10^-18 level}, journal = {Nature}, volume = {506}, year = {2014}, month = {1/2014}, pages = {71-75}, doi = {10.1038/nature12941}, author = {Bloom, B. and T L Nicholson and James R. Williams and S. L. Campbell and M. Bishof and X. Zhang and W. Zhang and S. L. Bromley and Jun Ye} } @article { ISI:000332174900006, title = {Pairing effects in the nondegenerate limit of the two-dimensional Fermi gas}, journal = {PHYSICAL REVIEW A}, volume = {89}, number = {1}, year = {2014}, month = {JAN 17}, issn = {1050-2947}, doi = {10.1103/PhysRevA.89.013614}, author = {Barth, Marcus and Hofmann, Johannes} } @article {2674, title = {Photon number resolution enables quantum receiver for realistic coherent optical communications}, journal = {Nature Photonics}, year = {2014}, month = {17 November 2014}, doi = {10.1038/nphoton.2014.280}, author = {F. E. Becerra and J. Fan and A. Migdall} } @article { ISI:000329597600018, title = {Probing many-body interactions in an optical lattice clock}, journal = {ANNALS OF PHYSICS}, volume = {340}, number = {1}, year = {2014}, month = {JAN}, pages = {311-351}, issn = {0003-4916}, doi = {10.1016/j.aop.2013.11.002}, author = {Rey, A. M. and Gorshkov, A. V. and Kraus, C. V. and Martin, M. J. and Bishof, M. and Swallows, M. D. and Zhang, X. and Benko, C. and Ye, J. and Lemke, N. D. and Ludlow, A. D.} } @article { ISI:000348132200004, title = {Quantum non-Gaussian Depth of Single-Photon States}, journal = {PHYSICAL REVIEW LETTERS}, volume = {113}, number = {22}, year = {2014}, month = {NOV 25}, pages = {223603}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.113.223603}, author = {Straka, Ivo and Predojevic, Ana and Huber, Tobias and Lachman, Lukas and Butschek, Lorenz and Mikova, Martina and Micuda, Michal and Solomon, Glenn S. and Weihs, Gregor and Jezek, Miroslav and Filip, Radim} } @article { ISI:000349832400025, title = {Reconstruction of mode structure of faint light sources and its applications}, journal = {PHYSICA SCRIPTA}, volume = {T163}, year = {2014}, month = {DEC}, issn = {0031-8949}, doi = {10.1088/0031-8949/2014/T163/014024}, author = {Polyakov, Sergey V. and Goldschmidt, Elizabeth A. and Alan Migdall and Kueck, Stefan and Piacentini, Fabrizio and Brida, Giorgio and Degiovanni, Ivo P. and Berchera, Ivano Ruo and Genovese, Marco} } @article { ISI:000342107800001, title = {Resistive anisotropy due to spin-fluctuation scattering in the nematic phase of iron pnictides}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {12}, year = {2014}, month = {SEP 10}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.121104}, author = {Breitkreiz, Maxim and Brydon, P. M. R. and Timm, Carsten} } @article { ISI:000332222800003, title = {Robust quantum gates for singlet-triplet spin qubits using composite pulses}, journal = {PHYSICAL REVIEW A}, volume = {89}, number = {2}, year = {2014}, month = {FEB 11}, issn = {1050-2947}, doi = {10.1103/PhysRevA.89.022310}, author = {Wang, Xin and Bishop, Lev S. and Barnes, Edwin and Kestner, J. P. and S. Das Sarma} } @article { ISI:000345413500011, title = {Scattering resonances and bound states for strongly interacting Rydberg polaritons}, journal = {PHYSICAL REVIEW A}, volume = {90}, number = {5}, year = {2014}, month = {NOV 3}, issn = {1050-2947}, doi = {10.1103/PhysRevA.90.053804}, author = {Bienias, P. and Choi, S. and Firstenberg, O. and Maghrebi, M. F. and Gullans, M. and Lukin, M. D. and Gorshkov, A. V. and Buechler, H. P.} } @article {2344, title = {Second-harmonic generation using -quasi-phasematching in a GaAs whispering-gallery-mode microcavity}, journal = {Nature Communications}, volume = {5}, year = {2014}, pages = {3109}, doi = {10.1038/ncomms4109}, author = {Paulina S Kuo and Bravo-Abad, Jorge and Glenn S Solomon} } @article { ISI:000331645900098, title = {Single-layer graphene on silicon nitride micromembrane resonators}, journal = {JOURNAL OF APPLIED PHYSICS}, volume = {115}, number = {5}, year = {2014}, month = {FEB 7}, issn = {0021-8979}, doi = {10.1063/1.4862296}, author = {Silvan Schmid and Tolga Bagci and Emil Zeuthen and Jacob M Taylor and Herring, Patrick K. and Cassidy, Maja C. and Charles M Marcus and Luis Guillermo Villanueva and Amato, Bartolo and Boisen, Anja and Shin, Yong Cheol and Kong, Jing and Anders S Sorensen and Koji Usami and Eugene S Polzik} } @article { ISI:000341752900033, title = {Spectroscopic observation of SU(N)-symmetric interactions in Sr orbital magnetism}, journal = {SCIENCE}, volume = {345}, number = {6203}, year = {2014}, month = {SEP 19}, pages = {1467-1473}, issn = {0036-8075}, doi = {10.1126/science.1254978}, author = {Zhang, X. and Bishof, M. and S. L. Bromley and Kraus, C. V. and Safronova, M. S. and Zoller, P. and Rey, A. M. and Ye, J.} } @article { ISI:000333007900001, title = {Spiral antiferromagnets beyond the spin-wave approximation: Frustrated XY and Heisenberg models on the honeycomb lattice}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {9}, year = {2014}, month = {MAR 19}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.094413}, author = {Di Ciolo, Andrea and Carrasquilla, Juan and Becca, Federico and Rigol, Marcos and Victor M Galitski} } @article { ISI:000330626200005, title = {Strong coupling of single emitters interacting with phononic infrared antennae}, journal = {NEW JOURNAL OF PHYSICS}, volume = {16}, year = {2014}, month = {JAN 30}, issn = {1367-2630}, doi = {10.1088/1367-2630/16/1/013052}, author = {Esteban, Ruben and Javier Aizpurua and Garnett W Bryant} } @article { ISI:000332421900003, title = {Strong hyperfine-induced modulation of an optically driven hole spin in an InAs quantum dot}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {7}, year = {2014}, month = {FEB 28}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.075316}, author = {Carter, S. G. and Economou, Sophia E. and Greilich, A. and Barnes, Edwin and Sweeney, T. and Bracker, A. S. and Gammon, D.} } @article { ISI:000332415200006, title = {Superconducting pairing in the spin-density-wave phase of iron pnictides}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {5}, year = {2014}, month = {FEB 26}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.054515}, author = {Schmiedt, Jacob and Brydon, P. M. R. and Timm, Carsten} } @article { ISI:000333666300005, title = {Theory of dynamic nuclear polarization and feedback in quantum dots}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {16}, year = {2014}, month = {APR 2}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.165301}, author = {Economou, Sophia E. and Barnes, Edwin} } @article { ISI:000342234700001, title = {Transport in multiband systems with hot spots on the Fermi surface: Forward-scattering corrections}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {24}, year = {2014}, month = {JUN 6}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.245106}, author = {Breitkreiz, Maxim and Brydon, P. M. R. and Timm, Carsten} } @article { ISI:000332409100002, title = {Tunneling into the Mott insulator Sr2IrO4}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {8}, year = {2014}, month = {FEB 24}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.085125}, author = {Nichols, John and Bray-Ali, Noah and Ansary, Armin and Cao, Gang and Ng, Kwok-Wai} } @conference { ISI:000343107600003, title = {Ultra-short gates improve the performance of high-speed gated single-photon avalanche diodes}, booktitle = {ADVANCED PHOTON COUNTING TECHNIQUES VIII}, series = {Proceedings of SPIE}, volume = {9114}, year = {2014}, note = {Conference on Advanced Photon Counting Techniques VIII, Baltimore, MD, MAY 07-08, 2014}, isbn = {978-1-62841-051-8}, issn = {0277-786X}, doi = {10.1117/12.2050808}, author = {Restelli, Alessandro and Bienfang, Joshua C. and Migdall, Alan L.}, editor = {Itzler, MA and Campbell, JC} } @article {2685, title = {Universal and nonuniversal effective N-body interactions for ultracold harmonically trapped few-atom systems}, journal = {Phys. Rev. A}, volume = {90}, year = {2014}, month = {Oct}, pages = {043631}, doi = {10.1103/PhysRevA.90.043631}, url = {http://link.aps.org/doi/10.1103/PhysRevA.90.043631}, author = {Yin, X. Y. and Blume, D. and Johnson, P. R. and E. Tiesinga} } @article { ISI:000332222500002, title = {Valley-degenerate two-dimensional electrons in the lowest Landau level}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {4}, year = {2014}, month = {JAN 17}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.041107}, author = {Tomasz M Kott and Hu, Binhui and Brown, S. H. and B E Kane} } @article { ISI:000344914500023, title = {Which resonances in small metallic nanoparticles are plasmonic?}, journal = {JOURNAL OF OPTICS}, volume = {16}, number = {11}, year = {2014}, month = {NOV}, issn = {2040-8978}, doi = {10.1088/2040-8978/16/11/114022}, author = {Townsend, Emily and Bryant, Garnett W.} } @article { ISI:000341270400008, title = {Why Does Graphene Behave as a Weakly Interacting System?}, journal = {PHYSICAL REVIEW LETTERS}, volume = {113}, number = {10}, year = {2014}, month = {SEP 5}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.113.105502}, author = {Hofmann, Johannes and Barnes, Edwin and S. Das Sarma} } @article { ISI:000325846000008, title = {Aluminium(III) chloride hexahydrate: an efficient and versatile reagent in organic synthesis}, journal = {ARKIVOC}, number = {1, SI}, year = {2013}, pages = {243-263}, issn = {1551-7004}, author = {Saikat Das Sarma and Pahari, Pallab and Hazarika, Swapnali and Hazarika, Parasa and Borah, Manash Jyoti and Konwar, Dilip} } @article { ISI:000321837000023, title = {Analytically solvable two-level quantum systems and Landau-Zener interferometry}, journal = {PHYSICAL REVIEW A}, volume = {88}, number = {1}, year = {2013}, month = {JUL 15}, issn = {1050-2947}, doi = {10.1103/PhysRevA.88.013818}, author = {Barnes, Edwin} } @article { ISI:000322161300001, title = {Anomalous Edge States and the Bulk-Edge Correspondence for Periodically Driven Two-Dimensional Systems}, journal = {PHYSICAL REVIEW X}, volume = {3}, number = {3}, year = {2013}, month = {JUL 23}, issn = {2160-3308}, doi = {10.1103/PhysRevX.3.031005}, author = {Rudner, Mark S. and Lindner, Netanel H. and Berg, Erez and Levin, Michael} } @inbook { ISI:000325758700024, title = {Architectures}, booktitle = {QUANTUM ERROR CORRECTION}, year = {2013}, pages = {537-552}, isbn = {978-0-521-89787-7}, author = {Taylor, Jacob}, editor = {Lidar, DA and Brun, TA} } @conference { ISI:000355262504290, title = {Beating the Standard Quantum Limit for Nonorthogonal Multi-State Discrimination}, booktitle = {2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2013}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, JUN 09-14, 2013}, isbn = {978-1-55752-973-2}, issn = {2160-9020}, author = {Becerra, F. E. and J. Fan and Baumgartner, G. and Goldhar, J. and Kosloski, J. T. and Migdall, A.} } @article { ISI:000324113700040, title = {Boundary effects on quantum entanglement and its dynamics in a detector-field system}, journal = {Journal of High Energy Physics}, number = {8}, year = {2013}, month = {AUG}, issn = {1029-8479}, doi = {10.1007/JHEP08(2013)040}, author = {Zhou, Rong and Ryan O Behunin and Lin, Shih-Yuin and Bei-Lok Hu} } @article { ISI:000313030700004, title = {Coherent nonlocal transport in quantum wires with strongly coupled electrodes}, journal = {Phys. Rev. B}, volume = {87}, number = {4}, year = {2013}, month = {JAN 3}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.045403}, author = {Y Yang and G Fedorov and P Barbara and S E Shafranjuk and Benjamin K Cooper and R M Lewis and Christopher J Lobb} } @article { ISI:000329910500055, title = {Commissioning of the Francium Trapping Facility at TRIUMF}, journal = {JOURNAL OF INSTRUMENTATION}, volume = {8}, year = {2013}, month = {DEC}, issn = {1748-0221}, doi = {10.1088/1748-0221/8/12/P12006}, author = {Tandecki, M. and Zhang, J. and Collister, R. and Aubin, S. and Behr, J. A. and Gomez, E. and Gwinner, G. and Luis A Orozco and Pearson, M. R.} } @article { ISI:000313408200001, title = {Control of conditional quantum beats in cavity QED: amplitude decoherence and phase shifts}, journal = {New J. Phys.}, volume = {15}, year = {2013}, month = {01/2013}, pages = {013017}, issn = {1367-2630}, doi = {10.1088/1367-2630/15/1/013017}, author = {A D Cimmarusti and C A Schroeder and B D Patterson and Luis A Orozco and P Barberis-Blostein and Howard J Carmichael} } @article {ISI:000318268800018, title = {Controlled coupling of photonic crystal cavities using photochromic tuning}, journal = {Appl. Phys. Lett.}, volume = {102}, number = {14}, year = {2013}, pages = {141118}, issn = {0003-6951}, doi = {10.1063/1.4802238}, author = {Cai, Tao and Ranojoy Bose and Glenn S Solomon and Edo Waks} } @article { ISI:000317823800008, title = {Controlling the spatial location of photoexcited electrons in semiconductor CdSe/CdS core/shell nanorods}, journal = {Phys. Rev. B}, volume = {87}, number = {15}, year = {2013}, month = {APR 22}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.155427}, author = {She, Chunxing and Garnett W Bryant and Demortiere, Arnaud and Shevchenko, Elena V. and Matthew Pelton} } @article { ISI:000318867100040, title = {DC SQUID Phase Qubit Coupled to an On-Chip LC Resonator}, journal = {IEEE Transactions on Applied Superconductivity}, volume = {23}, number = {3, 1}, year = {2013}, month = {JUN}, issn = {1051-8223}, doi = {10.1109/TASC.2013.2237876}, author = {R P Budoyo and Benjamin K Cooper and Zaretskey, V. and Ballard, C. J. and Jeffrey R Anderson and Christopher J Lobb and F C Wellstood} } @conference { ISI:000355262505007, title = {Demonstrating High Symmetric Single-Mode Single-Photon Heralding Efficiency in Spontaneous Parametric Downconversion}, booktitle = {2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2013}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, JUN 09-14, 2013}, isbn = {978-1-55752-973-2}, issn = {2160-9020}, author = {Pereira, M. and Becerra, F. and B. L. Glebov and J. Fan and S. W. Nam and Migdall, A.} } @article { ISI:000318488000013, title = {Demonstration of a dynamic bandpass frequency filter in a rare-earth ion-doped crystal}, journal = {JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS}, volume = {30}, number = {5}, year = {2013}, month = {MAY}, pages = {1173-1177}, issn = {0740-3224}, doi = {10.1364/JOSAB.30.001173}, author = {Beavan, Sarah E. and Goldschmidt, Elizabeth A. and Sellars, Matthew J.} } @conference { ISI:000333963600079, title = {Demonstration of Nonorthogonal Multi-State Discrimination Below the Standard Quantum Limit}, booktitle = {2013 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES}, year = {2013}, note = {IEEE-Photonics-Society Summer Topical Meeting, Waikoloa, HI, JUL 08-10, 2013}, pages = {166}, isbn = {978-1-4673-5060-0; 978-1-4673-5059-4}, author = {Becerra, F. E. and J. Fan and Baumgartner, G. and Goldhar and Kosloski, J. T. and Migdall, A.} } @article {ISI:000321293200001, title = {Direct observation of zitterbewegung in a Bose-Einstein condensate}, journal = {New J. Phys.}, volume = {15}, year = {2013}, month = {jul}, pages = {073011}, issn = {1367-2630}, doi = {10.1088/1367-2630/15/7/073011}, author = {Lindsay J LeBlanc and Matthew C Beeler and Karina Jim{\'e}nez-Garc{\'\i}a and Abigail R Perry and Seiji Sugawa and Ross A Williams and Ian B Spielman} } @article {ISI:000313421800006, title = {Driving Phase Slips in a Superfluid Atom Circuit with a Rotating Weak Link}, journal = {Phys. Rev. Lett.}, volume = {110}, number = {2}, year = {2013}, pages = {060504}, keywords = {CMAMO, Multiple Fellows}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.025302}, author = {Kevin C Wright and R B Blakestad and Christopher J Lobb and William D Phillips and Gretchen K Campbell} } @conference { ISI:000355262505029, title = {Dynamic Stark effect in a quantum dot strongly coupled to a cavity}, booktitle = {2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2013}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, JUN 09-14, 2013}, isbn = {978-1-55752-973-2}, issn = {2160-9020}, author = {Choudhury, Kaushik Roy and Bose, Ranojoy and Waks, Edo} } @article {2546, title = {Dynamical quantum correlations of Ising models on an arbitrary lattice and their resilience to decoherence}, journal = {NEW JOURNAL OF PHYSICS}, volume = {15}, year = {2013}, month = {NOV 7}, pages = {113008}, issn = {1367-2630}, doi = {10.1088/1367-2630/15/11/113008}, author = {Foss-Feig, M. and Hazzard, K. R. A. and Bollinger, J. J. and Rey, A. M. and Clark, C. W.} } @conference { ISI:000323339700016, title = {Effective Jaynes-Cummings model from on-chip filter in a dc SQUID phase qubit}, booktitle = {QUANTUM INFORMATION AND COMPUTATION XI}, series = {Proceedings of SPIE}, volume = {8749}, year = {2013}, note = {Conference on Quantum Information and Computation XI, Baltimore, MD, MAY 02-03, 2013}, isbn = {978-0-8194-9540-2}, issn = {0277-786X}, doi = {10.1117/12.2016272}, author = {Cooper, B. K. and Budoyo, R. P. and Zaretskey, V. and Ballard, C. J. and Anderson, J. R. and Lobb, C. J. and Wellstood, F. C.}, editor = {Donkor, E and Pirich, AR and Brandt, HE} } @article { ISI:000326148700059, title = {Evidence for hydrogen two-level systems in atomic layer deposition oxides}, journal = {APPLIED PHYSICS LETTERS}, volume = {103}, number = {16}, year = {2013}, month = {OCT 14}, issn = {0003-6951}, doi = {10.1063/1.4826253}, author = {Khalil, M. S. and Stoutimore, M. J. A. and Gladchenko, S. and Holder, A. M. and Musgrave, C. B. and Kozen, A. C. and Rubloff, G. and Liu, Y. Q. and Gordon, R. G. and Yum, J. H. and Banerjee, S. K. and Lobb, C. J. and Osborn, K. D.} } @article { ISI:000325362500001, title = {Exact Classification of Landau-Majorana-Stuckelberg-Zener Resonances by Floquet Determinants}, journal = {Phys. Rev. Lett.}, volume = {111}, number = {13}, year = {2013}, month = {SEP 25}, pages = {130405}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.111.130405}, author = {Ganeshan, Sriram and Barnes, Edwin and S. Das Sarma} } @article {2407, title = {Experimental demonstration of a receiver beating the standard quantum limit for multiple nonorthogonal state discrimination}, journal = {Nature Photonics}, volume = {7}, year = {2013}, month = {1/2013}, pages = {147-152}, doi = {10.1038/nphoton.2012.316}, author = {Francisco E Becerra and Jingyun Fan and G. Baumgartner and Goldhar, Julius and T. Kosloski and Alan L Migdall} } @article { ISI:000315572200022, title = {Experimental Test of an Event-Based Corpuscular Model Modification as an Alternative to Quantum Mechanics}, journal = {J. Phys. Soc. Jpn.}, volume = {82}, number = {3}, year = {2013}, month = {MAR}, issn = {0031-9015}, doi = {10.7566/JPSJ.82.034004}, author = {Giorgio Brida and Ivo P Degiovanni and Marco Genovese and Alan L Migdall and Fabrizio Piacentini and Sergey V Polyakov and Traina, Paolo} } @conference { ISI:000326980500015, title = {Feedback in a cavity QED system for control of quantum beats}, booktitle = {ICAP 2012 - 23RD INTERNATIONAL CONFERENCE ON ATOMIC PHYSICS}, series = {EPJ Web of Conferences}, volume = {57}, year = {2013}, note = {23rd International Conference on Atomic Physics (ICAP), Ecole Polytechnique, FRANCE, JUL 23-27, 2012}, issn = {2100-014X}, doi = {10.1051/epjconf/20135703005}, author = {Cimmarusti, A. D. and Patterson, B. D. and Schroeder, C. A. and Orozco, L. A. and Barberis-Blostein, P. and Carmichael, H. J.}, editor = {Dulieu, O and Grangier, P and Leduc, M and Perrin, H} } @article { ISI:000316660000012, title = {Feshbach resonances, weakly bound molecular states, and coupled-channel potentials for cesium at high magnetic fields}, journal = {Phys. Rev. A}, volume = {87}, number = {3}, year = {2013}, month = {MAR 25}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.032517}, author = {Martin Berninger and Alessandro Zenesini and Bo Huang and Walter Harm and Naegerl, Hanns-Christoph and Francesca Ferlaino and Rudolf Grimm and Paul S Julienne and Jeremy M Hutson} } @article { ISI:000313422800001, title = {Feshbach spectroscopy of an ultracold mixture of Rb-85 and Cs-133}, journal = {Phys. Rev. A}, volume = {87}, number = {1}, year = {2013}, month = {JAN 11}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.010703}, author = {Cho, Hung-Wen and McCarron, Daniel J. and Koeppinger, Michael P. and Jenkin, Daniel L. and Butler, Kirsteen L. and Paul S Julienne and Blackley, Caroline L. and Le Sueur, C. Ruth and Jeremy M Hutson and Cornish, Simon L.} } @conference { ISI:000323425900005, title = {Gigahertz-gated InGaAs SPAD system with avalanche charge sensitivity approaching the fundamental limit}, booktitle = {ADVANCED PHOTON COUNTING TECHNIQUES VII}, series = {Proceedings of SPIE}, volume = {8727}, year = {2013}, note = {Conference on Advanced Photon Counting Techniques VII, Baltimore, MD, MAY 01-02, 2013}, isbn = {978-0-8194-9518-1}, issn = {0277-786X}, doi = {10.1117/12.2016087}, author = {Restelli, Alessandro and Bienfang, Joshua C. and Migdall, Alan L.}, editor = {Itzler, MA and Campbell, JC} } @article { ISI:000323481000003, title = {Gradient echo memory in an ultra-high optical depth cold atomic ensemble}, journal = {NEW JOURNAL OF PHYSICS}, volume = {15}, year = {2013}, month = {AUG 23}, issn = {1367-2630}, doi = {10.1088/1367-2630/15/8/085027}, author = {Sparkes, B. M. and Bernu, J. and Hosseini, M. and Geng, J. and Glorieux, Q. and Altin, P. A. and Lam, P. K. and Robins, N. P. and Buchler, B. C.} } @article {1951, title = {Higher order mode propagation in ultrathin optical fibers for atom traps}, journal = {Proc. SPIE 8637, Complex Light and Optical Forces VII, 86370X }, year = {2013}, abstract = {We have demonstrated efficient propagation of the first excited TE01, TM01, and HE21 modes in a nanofiber with a radius of 400 nm. As we decrease the taper angle from 4 mrad to 1 mrad, the propagation becomes more adiabatic and the transmission improves from 20\% to 85\%. We have also demonstrated that the choice of drawn fiber can have a significant impact on the propagation characteristics.

}, doi = {10.1117/12.2004429}, url = {http://dx.doi.org/10.1117/12.2004429}, author = {Fredrik K Fatemi and Sylvain Ravets and Jonathan E Hoffman and Guy Beadie and Steven L Rolston and Luis A Orozco} } @conference { ISI:000326703000013, title = {A hybrid quantum system of atoms trapped on ultrathin optical fibers coupled to superconductors}, booktitle = {QUANTUM COMMUNICATIONS AND QUANTUM IMAGING XI}, series = {Proceedings of SPIE}, volume = {8875}, year = {2013}, note = {Conference on Quantum Communications and Quantum Imaging XI, San Diego, CA, AUG 26-29, 2013}, isbn = {978-0-8194-9725-3}, issn = {0277-786X}, doi = {10.1117/12.2024362}, author = {Rolston, S. L. and Anderson, J. R. and Chukwu, U. and Grover, J. and Hertzberg, J. B. and Hoffman, J. E. and Kordell, P. and Lee, J. and Lobb, C. J. and Orozco, L. A. and Ravets, S. and Solano, P. and Voigt, K. D. and Wellstood, F. C. and Wong-Campos, J. D. and Beadie, G. and Fatemi, F. K.}, editor = {Meyers, RE and Shih, Y and Deacon, KS} } @article { ISI:000327145900007, title = {Hyperfine and vibrational structure of weakly bound levels of the lowest 1(g) state of molecular Rb-87(2)}, journal = {PHYSICAL REVIEW A}, volume = {88}, number = {5}, year = {2013}, month = {NOV 13}, issn = {1050-2947}, doi = {10.1103/PhysRevA.88.052509}, author = {Tsai, Chin-Chun and Bergeman, T. and E. Tiesinga and Julienne, P. S. and Heinzen, D. J.} } @article {1914, title = {Implementation of generalized quantum measurements for unambiguous discrimination of multiple non-orthogonal coherent states}, journal = {Nat. Comm.}, volume = {4}, year = {2013}, pages = {2028}, doi = {10.1038/ncomms3028}, author = {Francisco E Becerra and Jingyun Fan and Alan L Migdall} } @inbook { ISI:000319020500005, title = {LIGHT INDUCED GAUGE FIELDS FOR ULTRACOLD NEUTRAL ATOMS}, booktitle = {ANNUAL REVIEW OF COLD ATOMS AND MOLECULES, VOL 1}, series = {Annual Review of Cold Atoms and Molecules}, volume = {1}, year = {2013}, pages = {145-187}, isbn = {978-981-4440-39-4}, issn = {2315-4926}, author = {Ian B Spielman}, editor = {Madison, KW and Wang, YQ and Rey, AM and Bongs, K} } @article {2108, title = {A low-loss photonic silica nanofiber for higher-order modes}, journal = {Optics Express}, volume = {21}, year = {2013}, pages = {18325}, doi = {http://dx.doi.org/10.1364/OE.21.018325}, url = {http://www.opticsinfobase.org/oe/fulltext.cfm?uri=oe-21-15-18325\&id=259647}, author = {Sylvain Ravets and Jonathan E Hoffman and Luis A Orozco and Steven L Rolston and Guy Beadie and Fredrik K Fatemi} } @article { ISI:000317190800014, title = {Magnetic Flux Noise in dc SQUIDs: Temperature and Geometry Dependence}, journal = {Phys. Rev. Lett.}, volume = {110}, number = {14}, year = {2013}, month = {APR 5}, pages = {147002}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.147002}, author = {S M Anton and J S Birenbaum and S R O{\textquoteright}Kelley and V Bolkhovsky and D A Braje and G Fitch and M Neeley and G C Hilton and H M Cho and K D Irwin and F C Wellstood and Oliver, W. D. and A Shnirman and Clarke, John} } @article { ISI:000325502400003, title = {Mechanism for controlling the exciton fine structure in quantum dots using electric fields: Manipulation of exciton orientation and exchange splitting at the atomic scale}, journal = {Phys. Rev. B}, volume = {88}, number = {16}, year = {2013}, month = {OCT 7}, issn = {1098-0121}, doi = {10.1103/PhysRevB.88.161301}, author = {Garnett W Bryant and Natalia Malkova and Sims, James} } @conference { ISI:000355262504294, title = {Mode reconstruction by multi-photon statistics}, booktitle = {2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)}, series = {Conference on Lasers and Electro-Optics}, year = {2013}, note = {Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, JUN 09-14, 2013}, isbn = {978-1-55752-973-2}, issn = {2160-9020}, author = {Goldschmidt, Elizabeth A. and Polyakov, Sergey V. and Alan Migdall and Peters, Silke and Kueck, Stefan and Piacentini, Fabrizio and Berchera, Ivano Ruo and Brida, Giorgio and Degiovanni, Ivo P. and Genovese, Marco} } @article {1957, title = {Mode reconstruction of a light field by multi-photon statistics}, journal = {Phys. Rev. A}, volume = {88}, year = {2013}, chapter = {013822}, url = {http://link.aps.org/doi/10.1103/PhysRevA.88.013822}, author = {Elizabeth A Goldschmidt and Fabrizio Piacentini and Ivano Ruo Berchera and Sergey V Polyakov and Silke Peters and Stefan Kuck and Giorgio Brida and Ivo P Degiovanni and Alan L Migdall and Marco Genovese} } @article { ISI:000321837000027, title = {Mode reconstruction of a light field by multiphoton statistics}, journal = {Phys. Rev. A}, volume = {88}, number = {1}, year = {2013}, month = {JUL 15}, pages = {013822}, issn = {1050-2947}, doi = {10.1103/PhysRevA.88.013822}, author = {Elizabeth A Goldschmidt and Fabrizio Piacentini and Ivano Ruo Berchera and Sergey V Polyakov and Silke Peters and Kueck, Stefan and Giorgio Brida and Ivo P Degiovanni and Alan L Migdall and Marco Genovese} } @article {2383, title = {Nature of the phases in the frustrated XY model on the honeycomb lattice}, journal = {Phys. Rev. B}, volume = {88}, year = {2013}, month = {Dec}, pages = {241109}, doi = {10.1103/PhysRevB.88.241109}, url = {http://link.aps.org/doi/10.1103/PhysRevB.88.241109}, author = {Carrasquilla, Juan and Andrea Di Ciolo and Becca, Federico and Victor M Galitski and Rigol, Marcos} } @article { ISI:000317190800002, title = {Noise-Resistant Control for a Spin Qubit Array}, journal = {Phys. Rev. Lett.}, volume = {110}, number = {14}, year = {2013}, month = {APR 5}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.140502}, author = {J P Kestner and Wang, Xin and Bishop, Lev S. and Barnes, Edwin and S. Das Sarma} } @article { ISI:000325402000068, title = {Note: Pneumatically actuated and kinematically positioned optical mounts compatible with laser-cooling experiments}, journal = {Rev. Sci. Instrum.}, volume = {84}, number = {9}, year = {2013}, month = {SEP}, issn = {0034-6748}, doi = {10.1063/1.4819744}, author = {Roger C Brown and Steven Olmschenk and Wu, Saijun and A M Dyckovsky and R Wyllie and J V Porto} } @article { ISI:000329437000003, title = {Observation of Autler-Townes effect in a dispersively dressed Jaynes-Cummings system}, journal = {NEW JOURNAL OF PHYSICS}, volume = {15}, year = {2013}, month = {DEC 5}, issn = {1367-2630}, doi = {10.1088/1367-2630/15/12/125007}, author = {B Suri and Z K Keane and Ruskov, R. and Bishop, Lev S. and Tahan, C. and S Novikov and J E Robinson and F C Wellstood and B S Palmer} } @conference { ISI:000355316300624, title = {Optical Readout of Coupling Between a Nanomembrane and an LC Circuit at Room Temperature}, booktitle = {2013 CONFERENCE ON AND INTERNATIONAL QUANTUM ELECTRONICS CONFERENCE LASERS AND ELECTRO-OPTICS EUROPE (CLEO EUROPE/IQEC)}, year = {2013}, note = {Conference on Lasers and Electro-Optics Europe \& International Quantum Electronics Conference (CLEO/Europe-IQEC), Munich, GERMANY, MAY 12-16, 2013}, isbn = {978-1-4799-0594-2}, author = {Bagci, T. and Simonsen, A. and Zeuthen, E. and Taylor, J. M. and Villanueva, L. G. and Schmid, S. and Sorensen, A. and Schliesser, A. and Usami, K. and Polzik, E. S.} } @article { ISI:000317963700006, title = {Oscillator-field model of moving mirrors in quantum optomechanics}, journal = {Phys. Rev. A}, volume = {87}, number = {4}, year = {2013}, month = {APR 24}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.043832}, author = {Galley, Chad R. and Ryan O Behunin and Bei-Lok Hu} } @article {ISI:000321262500005, title = {Photon-number-resolved detection of photon-subtracted thermal light}, journal = {Optics Letters}, volume = {38}, number = {13}, year = {2013}, month = {jul}, pages = {2171}, issn = {0146-9592}, doi = {10.1364/OL.38.002171}, author = {Zhai, Yanhua and Francisco E Becerra and Boris L Glebov and Wen, Jianming and Adriana E Lita and Calkins, Brice and Gerrits, Thomas and Jingyun Fan and Sae Woo Nam and Alan L Migdall} } @article { ISI:000323202400001, title = {Practical Implementation of a Test of Event-Based Corpuscular Model as an Alternative to Quantum Mechanics}, journal = {Foundations of Physics}, volume = {43}, number = {8}, year = {2013}, month = {AUG}, pages = {913-922}, issn = {0015-9018}, doi = {10.1007/s10701-013-9718-4}, author = {Sergey V Polyakov and Fabrizio Piacentini and Traina, Paolo and Ivo P Degiovanni and Alan L Migdall and Giorgio Brida and Marco Genovese} } @article { ISI:000316415500007, title = {Quantum dot-quantum dot interactions mediated by a metal nanoparticle: Towards a fully quantum model}, journal = {Phys. Rev. B}, volume = {87}, number = {12}, year = {2013}, month = {MAR 21}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.125423}, author = {Ryan D Artuso and Garnett W Bryant} } @article { ISI:000315727700009, title = {Quantum interference and light polarization effects in unresolvable atomic lines: Application to a precise measurement of the Li-6,Li-7 D-2 lines}, journal = {Phys. Rev. A}, volume = {87}, number = {3}, year = {2013}, month = {MAR 7}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.032504}, author = {Roger C Brown and Wu, Saijun and J V Porto and Sansonetti, Craig J. and C E Simien and Brewer, Samuel M. and Tan, Joseph N. and J D Gillaspy} } @article {2337, title = {A quantum logic gate between a solid-state quantum bit and a photon}, journal = {Nature Photonics}, volume = {7}, year = {2013}, pages = {373}, doi = {10.1038/nphoton.2013.48}, url = {http://www.nature.com/nphoton/journal/v7/n5/full/nphoton.2013.48.html}, author = {Kim, Hyochul and Ranojoy Bose and Thomas C Shen and Glenn S Solomon and Edo Waks} } @article {1944, title = {Quantum-Dot-Based Resonant Exchange Qubit}, journal = {Phys. Rev. Lett.}, volume = {111}, year = {2013}, month = {Jul}, pages = {050501}, doi = {10.1103/PhysRevLett.111.050501}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.111.050501}, author = {J Medford and J Beil and Jacob M Taylor and E I Rashba and H Lu and A C Gossard and Charles M Marcus} } @article { ISI:000323570800009, title = {Raman-Induced Interactions in a Single-Component Fermi Gas Near an s-Wave Feshbach Resonance}, journal = {Phys. Rev. Lett.}, volume = {111}, number = {9}, year = {2013}, month = {AUG 26}, pages = {095301}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.111.095301}, author = {Ross A Williams and Matthew C Beeler and Lindsay J LeBlanc and Karina Jim{\'e}nez-Garc{\'\i}a and Ian B Spielman} } @article { ISI:000322374300050, title = {Reply to Comment on "Experimental Test of an Event-Based Corpuscular Model Modification as an Alternative to Quantum Mechanics{\textquoteright}{\textquoteright}}, journal = {J. Phys. Soc. Jpn.}, volume = {82}, number = {8}, year = {2013}, month = {AUG}, issn = {0031-9015}, doi = {10.7566/JPSJ.82.086002}, author = {Giorgio Brida and Ivo P Degiovanni and Marco Genovese and Alan L Migdall and Fabrizio Piacentini and Sergey V Polyakov and Traina, Paolo} } @article { ISI:000313006100019, title = {Scaling of the Low-Energy Structure in Above-Threshold Ionization in the Tunneling Regime: Theory and Experiment}, journal = {PHYSICAL REVIEW LETTERS}, volume = {110}, number = {1}, year = {2013}, month = {JAN 2}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.013001}, author = {Guo, L. and Han, S. S. and Liu, X. and Cheng, Y. and Xu, Z. Z. and J. Fan and Chen, J. and Chen, S. G. and Becker, W. and Blaga, C. I. and DiChiara, A. D. and Sistrunk, E. and Agostini, P. and DiMauro, L. F.} } @article { ISI:000327149100008, title = {Scattering lengths in isotopologues of the RbYb system}, journal = {PHYSICAL REVIEW A}, volume = {88}, number = {5}, year = {2013}, month = {NOV 20}, issn = {1050-2947}, doi = {10.1103/PhysRevA.88.052708}, author = {Borkowski, Mateusz and Zuchowski, Piotr S. and Ciurylo, Roman and Julienne, Paul S. and Kedziera, Dariusz and Mentel, Lukasz and Tecmer, Pawel and Muenchow, Frank and Bruni, Cristian and Goerlitz, Axel} } @article { ISI:000324172800014, title = {Self-consistent measurement and state tomography of an exchange-only spin qubit}, journal = {Nat. Nano.}, volume = {8}, number = {9}, year = {2013}, month = {SEP}, pages = {654}, issn = {1748-3387}, doi = {10.1038/NNANO.2013.168}, author = {J Medford and J Beil and Jacob M Taylor and S D Bartlett and A C Doherty and E I Rashba and D P DiVincenzo and H Lu and A C Gossard and Charles M Marcus} } @article { ISI:000318268800004, title = {Single-photon detection efficiency up to 50\% at 1310 nm with an InGaAs/InP avalanche diode gated at 1.25 GHz}, journal = {Appl. Phys. Lett.}, volume = {102}, number = {14}, year = {2013}, month = {APR 8}, issn = {0003-6951}, doi = {10.1063/1.4801939}, author = {Restelli, Alessandro and Bienfang, Joshua C. and Alan L Migdall} } @article {2336, title = {Six-electron semiconductor double quantum dot qubits}, journal = {Phys. Rev. B}, volume = {88}, year = {2013}, month = {Nov}, pages = {195131}, doi = {10.1103/PhysRevB.88.195131}, url = {http://link.aps.org/doi/10.1103/PhysRevB.88.195131}, author = {Nielsen, Erik and Barnes, Edwin and J P Kestner and S. Das Sarma} } @article {1911, title = {The spin Hall effect in a quantum gas}, journal = {Nature}, volume = {498}, year = {2013}, month = {06/2013}, pages = {201}, keywords = {Spin-orbit coupling}, doi = {DOI:10.1038/nature12185}, url = {http://www.nature.com/nature/journal/v498/n7453/full/nature12185.html}, author = {Matthew C Beeler and Ross A Williams and Karina Jim{\'e}nez-Garc{\'\i}a and Lindsay J LeBlanc and Abigail R Perry and Ian B Spielman} } @article { ISI:000321752400022, title = {Spinor Dynamics in an Antiferromagnetic Spin-1 Thermal Bose Gas}, journal = {Phys. Rev. Lett.}, volume = {111}, number = {2}, year = {2013}, month = {JUL 9}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.111.025301}, author = {H K Pechkis and J P Wrubel and Arne Schwettmann and P F Griffin and Ryan Barnett and Eite Tiesinga and Paul D Lett} } @article { ISI:000318151600084, title = {Storage and retrieval of collective excitations on a long-lived spin transition in a rare-earth ion-doped crystal}, journal = {OPTICS EXPRESS}, volume = {21}, number = {8}, year = {2013}, month = {APR 22}, pages = {10087-10094}, issn = {1094-4087}, doi = {10.1364/OE.21.010087}, author = {Goldschmidt, E. A. and Beavan, S. E. and Polyakov, S. V. and Migdall, A. L. and Sellars, M. J.} } @article { ISI:000314761100027, title = {Surface states in negative-band-gap semiconductor films: Intrinsic or topological?}, journal = {Physica B: Condensed Matter}, volume = {410}, year = {2013}, month = {FEB 1}, pages = {147-156}, issn = {0921-4526}, doi = {10.1016/j.physb.2012.11.013}, author = {Natalia Malkova and Garnett W Bryant} } @article {2346, title = {Threshold for creating excitations in a stirred superfluid ring}, journal = {Phys. Rev. A}, volume = {88}, year = {2013}, month = {Dec}, pages = {063633}, doi = {10.1103/PhysRevA.88.063633}, url = {http://link.aps.org/doi/10.1103/PhysRevA.88.063633}, author = {Kevin C Wright and R B Blakestad and Christopher J Lobb and William D Phillips and Gretchen K Campbell} } @article { ISI:000320949600003, title = {Topological Floquet spectrum in three dimensions via a two-photon resonance}, journal = {Phys. Rev. B}, volume = {87}, number = {23}, year = {2013}, month = {JUN 24}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.235131}, author = {Lindner, Netanel H. and Doron L. Bergman and Refael, Gil and Victor M Galitski} } @inbook { ISI:000323088400002, title = {Ultracold Few-Body Systems}, booktitle = {ADVANCES IN ATOMIC, MOLECULAR, AND OPTICAL PHYSICS, VOL 62}, series = {Advances In Atomic Molecular and Optical Physics}, volume = {62}, year = {2013}, pages = {1-115}, isbn = {978-0-12-408090-4}, issn = {1049-250X}, doi = {10.1016/B978-0-12-408090-4.00001-3}, author = {Wang, Yujun and D{\textquoteright}Incao, Jose P. and Esry, Brett D.}, editor = {Arimondo, E and Berman, PR and Lin, CC} } @article { ISI:000317193400004, title = {Unconventional spin-density waves in dipolar Fermi gases}, journal = {Phys. Rev. A}, volume = {87}, number = {4}, year = {2013}, month = {APR 5}, pages = {043604}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.043604}, author = {S G Bhongale and Ludwig Mathey and Tsai, Shan-Wen and Charles W Clark and Zhao, Erhai} } @article {ISI:000320953300001, title = {Variational Monte Carlo study of spin-polarization stability of fractional quantum Hall states against realistic effects in half-filled Landau levels}, journal = {Phys. Rev. B}, volume = {87}, number = {23}, year = {2013}, month = {jun}, pages = {235134}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.235134}, author = {J Biddle and Michael R Peterson and S. Das Sarma} } @article {2536, title = {All-optical tuning of a quantum dot in a coupled cavity system}, journal = {APPLIED PHYSICS LETTERS}, volume = {100}, year = {2012}, month = {JUN 4}, pages = {231107}, issn = {0003-6951}, doi = {10.1063/1.4719065}, author = {Bose, Ranojoy and Cai, Tao and Solomon, Glenn S. and Waks, Edo} } @article { ISI:000307283300001, title = {Analytically Solvable Driven Time-Dependent Two-Level Quantum Systems}, journal = {PHYSICAL REVIEW LETTERS}, volume = {109}, number = {6}, year = {2012}, month = {AUG 7}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.060401}, author = {Barnes, Edwin and S. Das Sarma} } @article { ISI:000310200100018, title = {Atomic Quantum Simulation of Dynamical Gauge Fields Coupled to Fermionic Matter: From String Breaking to Evolution after a Quench}, journal = {PHYSICAL REVIEW LETTERS}, volume = {109}, number = {17}, year = {2012}, month = {OCT 23}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.175302}, author = {Banerjee, D. and Dalmonte, M. and Mueller, M. and Rico, E. and Stebler, P. and Wiese, U. -J. and Zoller, P.} } @article {ISI:000302238900006, title = {Bond Order Solid of Two-Dimensional Dipolar Fermions}, journal = {Phys. Rev. Lett.}, volume = {108}, number = {14}, year = {2012}, pages = {145301}, abstract = {The recent experimental realization of dipolar Fermi gases near or below quantum degeneracy provides an opportunity to engineer Hubbard-like models with long-range interactions. Motivated by these experiments, we chart out the theoretical phase diagram of interacting dipolar fermions on the square lattice at zero temperature and half filling. We show that, in addition to p-wave superfluid and charge density wave order, two new and exotic types of bond order emerge generically in dipolar fermion systems. These phases feature homogeneous density but periodic modulations of the kinetic hopping energy between nearest or next-nearest neighbors. Similar, but manifestly different, phases of two-dimensional correlated electrons have previously only been hypothesized and termed {\textquoteleft}{\textquoteleft}density waves of nonzero angular momentum.{\textquoteright}{\textquoteright} Our results suggest that these phases can be constructed flexibly with dipolar fermions, using currently available experimental techniques.

}, keywords = {2012, Single Fellow}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.108.145301}, author = {S G Bhongale and Ludwig Mathey and Tsai, Shan-Wen and Charles W Clark and Zhao, Erhai} } @article { ISI:000299821100005, title = {Competing Topological Orders in the nu=12/5 Quantum Hall State}, journal = {PHYSICAL REVIEW LETTERS}, volume = {108}, number = {3}, year = {2012}, month = {JAN 20}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.108.036806}, author = {Bonderson, Parsa and Feiguin, Adrian E. and Moeller, Gunnar and Slingerland, J. K.} } @article {2411, title = {Composite pulses for robust universal control of singlet-triplet qubits}, journal = {Nature Communications}, volume = {3}, year = {2012}, month = {8/2012}, pages = {997}, doi = {10.1038/ncomms2003}, author = {Wang, Xin and Bishop, Lev S. and J P Kestner and Barnes, Edwin and Kai Sun and S. Das Sarma} } @article { ISI:000305739000006, title = {Detecting d-wave pairing and collective modes in fermionic condensates with Bragg scattering}, journal = {PHYSICAL REVIEW A}, volume = {85}, number = {6}, year = {2012}, month = {JUN 27}, issn = {1050-2947}, doi = {10.1103/PhysRevA.85.063619}, author = {Boyd, G. R. and Victor M Galitski and Yakovenko, V. M.} } @article {ISI:000307071200001, title = {Disorder-driven loss of phase coherence in a quasi-2D cold atom system}, journal = {New J. Phys.}, volume = {14}, year = {2012}, pages = {073024}, abstract = {We study the order parameter of a quasi-two-dimensional (quasi-2D) gas of ultracold atoms trapped in an optical potential in the presence of controllable disorder. Our results show that disorder drives phase fluctuations without significantly affecting the amplitude of the quasi-condensate order parameter. This is evidence that disorder can drive phase fluctuations in 2D systems, relevant to the phase-fluctuation mechanism for the superconductor-to-insulator phase transition (SIT) in disordered 2D superconductors.

}, keywords = {Single Fellow}, issn = {1367-2630}, doi = {10.1088/1367-2630/14/7/073024}, author = {Matthew C Beeler and Reed, M E W and Hong, T and Steven L Rolston} } @article {2533, title = {Effective renormalized multi-body interactions of harmonically confined ultracold neutral bosons}, journal = {NEW JOURNAL OF PHYSICS}, volume = {14}, year = {2012}, month = {MAY 25}, pages = {053037}, issn = {{1367-2630}}, doi = {10.1088/1367-2630/14/5/053037}, author = {Johnson, P. R. and Blume, D. and Yin, X. Y. and Flynn, W. F. and E. Tiesinga} } @article { ISI:000312452800075, title = {Efficient single-spatial-mode periodically-poled KTiOPO4 waveguide source for high-dimensional entanglement-based quantum key distribution}, journal = {OPTICS EXPRESS}, volume = {20}, number = {24}, year = {2012}, month = {NOV 19}, pages = {26868-26877}, issn = {1094-4087}, doi = {10.1364/OE.20.026868}, author = {Zhong, Tian and Wong, Franco N. C. and Restelli, Alessandro and Bienfang, Joshua C.} } @article { ISI:000311967000012, title = {An extremely low-noise heralded single-photon source: A breakthrough for quantum technologies}, journal = {APPLIED PHYSICS LETTERS}, volume = {101}, number = {22}, year = {2012}, month = {NOV 26}, issn = {0003-6951}, doi = {10.1063/1.4768288}, author = {Brida, G. and Degiovanni, I. P. and Genovese, M. and Piacentini, F. and Traina, P. and Della Frera, A. and Tosi, A. and Shehata, A. Bahgat and Scarcella, C. and Gulinatti, A. and Ghioni, M. and Polyakov, S. V. and Migdall, A. and Giudice, A.} } @article { ISI:000309815700008, title = {Intrinsic Electron-Phonon Resistivity of Bi2Se3 in the Topological Regime}, journal = {PHYSICAL REVIEW LETTERS}, volume = {109}, number = {15}, year = {2012}, month = {OCT 15}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.166801}, author = {Kim, Dohun and Li, Qiuzi and Syers, Paul and Butch, Nicholas P. and Paglione, Johnpierre and S. Das Sarma and Fuhrer, Michael S.} } @article {ISI:000312829800033, title = {Loop-structure stability of a double-well-lattice Bose-Einstein condensate}, journal = {Phys. Rev. A}, volume = {86}, number = {6}, year = {2012}, month = {dec}, pages = {063636}, keywords = {CMAMO, Multiple Fellows}, issn = {1050-2947}, doi = {10.1103/PhysRevA.86.063636}, author = {Hui, Hoi-Yin and Ryan Barnett and J V Porto and S. Das Sarma} } @article {2414, title = {Low-Photon-Number Optical Switching with a Single Quantum Dot Coupled to a Photonic Crystal Cavity}, journal = {Phys. Rev. Lett.}, volume = {108}, year = {2012}, month = {5/2012}, pages = {227402}, doi = {10.1103/PhysRevLett.108.227402}, author = {Ranojoy Bose and Deepak Sridharan and Kim, Hyochul and Glenn S Solomon and Edo Waks} } @article { ISI:000305032100003, title = {Measurements of Quasiparticle Tunneling Dynamics in a Band-Gap-Engineered Transmon Qubit}, journal = {PHYSICAL REVIEW LETTERS}, volume = {108}, number = {23}, year = {2012}, month = {JUN 8}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.108.230509}, author = {Sun, L. and DiCarlo, L. and Reed, M. D. and Catelani, G. and Bishop, Lev S. and Schuster, D. I. and Johnson, B. R. and Yang, Ge A. and Frunzio, L. and Glazman, L. and Devoret, M. H. and Schoelkopf, R. J.} } @article { ISI:000309589600001, title = {Nonperturbative Master Equation Solution of Central Spin Dephasing Dynamics}, journal = {PHYSICAL REVIEW LETTERS}, volume = {109}, number = {14}, year = {2012}, month = {OCT 5}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.140403}, author = {Barnes, Edwin and Cywinski, Lukasz and S. Das Sarma} } @article {2412, title = {Observation of a superfluid Hall effect}, journal = {Proceedings of the National Academy of Science}, volume = {109}, year = {2012}, month = {6/2012}, pages = {10811}, doi = {10.1073/pnas.1202579109}, author = {Lindsay J LeBlanc and Karina Jim{\'e}nez-Garc{\'\i}a and Ross A Williams and Matthew C Beeler and Abigail R Perry and William D Phillips and Ian B Spielman} } @article {Barnett2012, title = {Order by disorder in spin-orbit-coupled Bose-Einstein condensates}, journal = {Phys. Rev. A}, volume = {85}, number = {2}, year = {2012}, month = {feb}, pages = {023615}, keywords = {Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v85/i2/e023615}, author = {Ryan Barnett and Powell, Stephen and Gra{\ss}, Tobias and Maciej Lewenstein and S. Das Sarma} } @article {ISI:000304531100015, title = {Peierls Substitution in an Engineered Lattice Potential}, journal = {Phys. Rev. Lett.}, volume = {108}, number = {21}, year = {2012}, month = {may}, pages = {225303}, abstract = {Artificial gauge fields open the possibility to realize quantum many-body systems with ultracold atoms, by engineering Hamiltonians usually associated with electronic systems. In the presence of a periodic potential, artificial gauge fields may bring ultracold atoms closer to the quantum Hall regime. Here, we describe a one-dimensional lattice derived purely from effective Zeeman shifts resulting from a combination of Raman coupling and radio-frequency magnetic fields. In this lattice, the tunneling matrix element is generally complex. We control both the amplitude and the phase of this tunneling parameter, experimentally realizing the Peierls substitution for ultracold neutral atoms.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.108.225303}, author = {Karina Jim{\'e}nez-Garc{\'\i}a and Lindsay J LeBlanc and Ross A Williams and Matthew C Beeler and Abigail R Perry and Ian B Spielman} } @article {2417, title = {Signatures of Majorana Fermions in Hybrid Superconductor-Semiconductor Nanowire Devices}, journal = {Science}, volume = {336}, year = {2012}, month = {5/2012}, pages = {1003-1007}, chapter = {1003}, doi = {10.1126/science.1222360}, author = {V. Mourik and K. Zuo and S. M. Frolov and S. R. Plissard and E. P. A. M. Bakkers and L. P. Kouwenhoven} } @article { ISI:000311138200008, title = {Spontaneous creation and persistence of ground-state coherence in a resonantly driven intracavity atomic ensemble}, journal = {PHYSICAL REVIEW A}, volume = {86}, number = {5}, year = {2012}, month = {NOV 15}, issn = {1050-2947}, doi = {10.1103/PhysRevA.86.053816}, author = {Norris, D. G. and Cimmarusti, A. D. and Orozco, L. A. and Barberis-Blostein, P. and Carmichael, H. J.} } @article {ISI:000312012200026, title = {SU(3) Spin-Orbit Coupling in Systems of Ultracold Atoms}, journal = {Phys. Rev. Lett.}, volume = {109}, number = {23}, year = {2012}, month = {dec}, pages = {235308}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.235308}, author = {Ryan Barnett and Boyd, G R and Victor M Galitski} } @article { ISI:000308015500021, title = {Universal Conductance Fluctuations in Dirac Materials in the Presence of Long-range Disorder}, journal = {PHYSICAL REVIEW LETTERS}, volume = {109}, number = {9}, year = {2012}, month = {AUG 27}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.109.096801}, author = {Rossi, E. and Bardarson, J. H. and Fuhrer, M. S. and S. Das Sarma} } @article {Powell2011a, title = {Bogoliubov theory of interacting bosons on a lattice in a synthetic magnetic field}, journal = {Phys. Rev. A}, volume = {83}, number = {1}, year = {2011}, month = {jan}, pages = {013612}, keywords = {2011, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v83/i1/e013612}, author = {Powell, Stephen and Ryan Barnett and Sensarma, Rajdeep and S. Das Sarma} } @article {Zhao2011, title = {Chern numbers hiding in time-of-flight images}, journal = {Phys. Rev. A}, volume = {84}, number = {6}, year = {2011}, month = {dec}, pages = {063629}, abstract = {We present a technique for detecting topological invariants {\textendash} Chern numbers {\textendash} from time-of-flight images of ultra-cold atoms. We show that the Chern numbers of integer quantum Hall states of lattice fermions leave their fingerprints in the atoms{\textquoteright} momentum distribution. We analytically demonstrate that the number of local maxima in the momentum distribution is equal to the Chern number in two limiting cases, for large hopping anisotropy and in the continuum limit. In addition, our numerical simulations beyond these two limits show that these local maxima persist for a range of parameters. Thus, an everyday observable in cold atom experiments can serve as a useful tool to characterize and visualize quantum states with non-trivial topology.

}, keywords = {2011, Multiple Fellows}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v84/i6/e063629 http://arxiv.org/abs/1105.3100}, author = {Zhao, Erhai and Bray-Ali, Noah and Carl J Williams and Ian B Spielman and Indubala Satija} } @article {ISI:000296287300010, title = {Coalescence of Single Photons Emitted by Disparate Single-Photon Sources: The Example of InAs Quantum Dots and Parametric Down-Conversion Sources}, journal = {Phys. Rev. Lett.}, volume = {107}, number = {15}, year = {2011}, month = {oct}, pages = {157402}, abstract = {Single photons produced by fundamentally dissimilar physical processes will in general not be indistinguishable. We show how photons produced from a quantum dot and by parametric down-conversion in a nonlinear crystal can be manipulated to be indistinguishable. The measured two-photon coalescence probability is 16\%, and is limited by quantum-dot decoherence. Temporal filtering to the quantum-dot coherence time and accounting for detector time response increases this to 61\% while retaining 25\% of the events. This technique can connect different elements in a scalable quantum network.

}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.107.157402}, author = {Sergey V Polyakov and Andreas Muller and Flagg, Edward B. and Alexander Ling and Borjemscaia, Natalia and Edward Van Keuren and Alan L Migdall and Glenn S Solomon} } @article { ISI:000286878500002, title = {Competition between Pairing and Ferromagnetic Instabilities in Ultracold Fermi Gases near Feshbach Resonances}, journal = {PHYSICAL REVIEW LETTERS}, volume = {106}, number = {5}, year = {2011}, month = {FEB 1}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.106.050402}, author = {Pekker, David and Babadi, Mehrtash and Sensarma, Rajdeep and Zinner, Nikolaj and Pollet, Lode and Zwierlein, Martin W. and Demler, Eugene} } @article { ISI:000292922100015, title = {Electron-Nuclear Dynamics in a Quantum Dot under Nonunitary Electron Control}, journal = {PHYSICAL REVIEW LETTERS}, volume = {107}, number = {4}, year = {2011}, month = {JUL 20}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.107.047601}, author = {Barnes, Edwin and Economou, Sophia E.} } @article { ISI:000295484300003, title = {Entanglement measures for quasi-two-dimensional fractional quantum Hall states}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {12}, year = {2011}, month = {SEP 30}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.125141}, author = {Biddle, J. and Peterson, Michael R. and S. Das Sarma} } @article { ISI:000298559600005, title = {Exactly soluble models for fractional topological insulators in two and three dimensions}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {23}, year = {2011}, month = {DEC 27}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.235145}, author = {Levin, Michael and Burnell, F. J. and Koch-Janusz, Maciej and Stern, Ady} } @article {Brida2011, title = {Experimental realization of a low-noise heralded single-photon source}, journal = {Optics Express}, volume = {19}, number = {2}, year = {2011}, month = {jan}, pages = {1484}, publisher = {OSA}, abstract = {We present a heralded single-photon source with a much lower level of unwanted background photons in the output channel by using the herald photon to control a shutter in the heralded channel. The shutter is implemented using a simple field programable gate array controlled optical switch.}, keywords = {2011, Quantum information and processing, Quantum optics, Single Fellow}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-19-2-1484}, author = {Giorgio Brida and Ivo P Degiovanni and Marco Genovese and Alan L Migdall and Fabrizio Piacentini and Sergey V Polyakov and I Ruo Berchera} } @article {Baltrusch2011, title = {Fast and robust quantum computation with ionic Wigner crystals}, journal = {Phys. Rev. A}, volume = {83}, number = {4}, year = {2011}, month = {apr}, pages = {042319}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v83/i4/e042319}, author = {Baltrusch, J. and Negretti, A. and Jacob M Taylor and Tommaso Calarco} } @article {Hui2011, title = {Instabilities of bosonic spin currents in optical lattices}, journal = {Phys. Rev. A}, volume = {84}, number = {4}, year = {2011}, month = {oct}, pages = {043615}, keywords = {2011, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v84/i4/e043615}, author = {Hui, Hoi-Yin and Ryan Barnett and Sensarma, Rajdeep and S. Das Sarma} } @article {Bose2011a, title = {Large optical Stark shifts in semiconductor quantum dots coupled to photonic crystal cavities}, journal = {Appl. Phys. Lett.}, volume = {98}, number = {12}, year = {2011}, month = {mar}, pages = {121109}, keywords = {2011, CMAMO, gallium arsenide, III-V semiconductors, indium compounds, master equation, Multiple Fellows, photonic crystals, semiconductor quantum dots, Stark effect}, issn = {00036951}, url = {http://link.aip.org/link/?APPLAB/98/121109/1}, author = {Ranojoy Bose and Deepak Sridharan and Glenn S Solomon and Edo Waks} } @article {Biddle2011, title = {Localization in one-dimensional lattices with non-nearest-neighbor hopping: Generalized Anderson and Aubry-Andr{\'e} models}, journal = {Phys. Rev. B}, volume = {83}, number = {7}, year = {2011}, month = {feb}, pages = {075105}, keywords = {2011, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v83/i7/e075105 http://prb.aps.org/abstract/PRB/v83/i8/e089901}, author = {J Biddle and Priour, D. and Bin Wang and S. Das Sarma} } @article { ISI:000296290000009, title = {Master equation approach to the central spin decoherence problem: Uniform coupling model and role of projection operators}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {15}, year = {2011}, month = {OCT 18}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.155315}, author = {Barnes, Edwin and Cywinski, Lukasz and S. Das Sarma} } @article {Blatt2011, title = {Measurement of Optical Feshbach Resonances in an Ideal Gas}, journal = {Phys. Rev. Lett.}, volume = {107}, number = {7}, year = {2011}, month = {aug}, pages = {073202}, keywords = {2011}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v107/i7/e073202}, author = {Blatt, S and T L Nicholson and Bloom, B. and James E Williams and J W Thomsen and Paul S Julienne and Jun Ye} } @article {Behunin2011, title = {Nonequilibrium forces between atoms and dielectrics mediated by a quantum field}, journal = {Phys. Rev. A}, volume = {84}, number = {1}, year = {2011}, month = {jul}, pages = {012902}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v84/i1/e012902}, author = {Ryan O Behunin and Bei-Lok Hu} } @article { ISI:000297795900001, title = {Observation of High Coherence in Josephson Junction Qubits Measured in a Three-Dimensional Circuit QED Architecture}, journal = {PHYSICAL REVIEW LETTERS}, volume = {107}, number = {24}, year = {2011}, month = {DEC 5}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.107.240501}, author = {Paik, Hanhee and Schuster, D. I. and Bishop, Lev S. and Kirchmair, G. and Catelani, G. and Sears, A. P. and Johnson, B. R. and Reagor, M. J. and Frunzio, L. and Glazman, L. I. and Girvin, S. M. and Devoret, M. H. and Schoelkopf, R. J.} } @article {Bose2011, title = {Observation of strong coupling through transmission modification of a cavity-coupled photonic crystal waveguide}, journal = {Optics Express}, volume = {19}, number = {6}, year = {2011}, month = {mar}, pages = {5398}, publisher = {OSA}, abstract = {We investigate strong coupling between a single quantum dot (QD) and photonic crystal cavity through transmission modification of an evanescently coupled waveguide. Strong coupling is observed through modification of both the cavity scattering spectrum and waveguide transmission. We achieve an overall Q of 5800 and an exciton-photon coupling strength of 21 GHz for this integrated cavity-waveguide structure. The transmission contrast for the bare cavity mode is measured to be 24\%. These results represent important progress towards integrated cavity quantum electrodynamics using a planar photonic architecture.}, keywords = {2011, CMAMO, Integrated optics devices, Multiple Fellows, Quantum electrodynamics}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-19-6-5398}, author = {Ranojoy Bose and Deepak Sridharan and Glenn S Solomon and Edo Waks} } @article {Borkowski2011, title = {Photoassociative production of ultracold heteronuclear ytterbium molecules}, journal = {Phys. Rev. A}, volume = {84}, number = {3}, year = {2011}, month = {sep}, pages = {30702}, keywords = {2011, Coherent control of atomic interactions with photo, General theories and models of atomic and molecula, Interatomic potentials and forces, Laser-modified scattering and reactions}, issn = {1050-2947}, url = {http://adsabs.harvard.edu/abs/2011PhRvA..84c0702B}, author = {Mateusz Borkowski and Roman Ciurylo and Paul S Julienne and Yamazaki, Rekishu and Hara, Hideaki and Katsunari Enomoto and Taie, Shintaro and Seiji Sugawa and Takasu, Yosuke and Yoshiro Takahashi} } @article {Barnett2011a, title = {Prethermalization in quenched spinor condensates}, journal = {Phys. Rev. A}, volume = {84}, number = {2}, year = {2011}, month = {aug}, pages = {023606}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v84/i2/e023606}, author = {Ryan Barnett and Anatoli Polkovnikov and Vengalattore, Mukund} } @article {Benton2011, title = {Prototyping method for Bragg-type atom interferometers}, journal = {Phys. Rev. A}, volume = {84}, number = {4}, year = {2011}, month = {oct}, pages = {043648}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v84/i4/e043648}, author = {Benton, Brandon and Krygier, Michael and Heward, Jeffrey and Edwards, Mark and Charles W Clark} } @article {Barnett2011, title = {Quantum rotor theory of spinor condensates in tight traps}, journal = {Phys. Rev. A}, volume = {83}, number = {2}, year = {2011}, month = {feb}, pages = {023613}, keywords = {2011, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v83/i2/e023613}, author = {Ryan Barnett and Hui, Hoi-Yin and Chien-Hung Lin and Jay D Sau and S. Das Sarma} } @article {Sridharan2011, title = {A reversibly tunable photonic crystal nanocavity laser using photochromic thin film}, journal = {Optics Express}, volume = {19}, number = {6}, year = {2011}, month = {mar}, pages = {5551}, publisher = {OSA}, abstract = {We demonstrate a reversibly tunable photonic crystal quantum dot laser using a photochromic thin film. The laser is composed of a photonic crystal cavity with a bare cavity Q as high as 4500 coupled to a high density ensemble of indium arsenide quantum dots. By depositing a thin layer of photochromic material on the photonic crystal cavities, the laser can be optically tuned smoothly and reversibly over a wavelength range of 2.68 nm. Lasing is observed at temperatures as high as 80 K in the 900-1000 nm near-infrared wavelength range. The spontaneous emission coupling factor is measured to be as high as $\beta$ = 0.41, indicating that the laser operates in the high-$\beta$ regime.}, keywords = {2011, CMAMO, Lasers, Multiple Fellows, Nanophotonics and photonic crystals, tunable}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-19-6-5551}, author = {Deepak Sridharan and Ranojoy Bose and Kim, Hyochul and Glenn S Solomon and Edo Waks} } @article { ISI:000298115400004, title = {Screening of charged impurities with multielectron singlet-triplet spin qubits in quantum dots}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {23}, year = {2011}, month = {DEC 15}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.235309}, author = {Barnes, Edwin and Kestner, J. P. and Nguyen, N. T. T. and S. Das Sarma} } @article {Baumer2011, title = {Spatial separation in a thermal mixture of ultracold \^\174\Yb and \^\87\Rb atoms}, journal = {Phys. Rev. A}, volume = {83}, number = {4}, year = {2011}, month = {apr}, pages = {040702}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v83/i4/e040702}, author = {F Baumer and M{\"u}nchow, F. and G{\"o}rlitz, A. and Maxwell, S. and Paul S Julienne and Eite Tiesinga} } @article {Braun2011, title = {Superradiance of cold atoms coupled to a superconducting circuit}, journal = {Phys. Rev. A}, volume = {83}, number = {6}, year = {2011}, month = {jun}, pages = {062305}, keywords = {2011}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v83/i6/e062305}, author = {Braun, Daniel and Jonathan E Hoffman and Eite Tiesinga} } @article {Williams2011, title = {Synthetic Partial Waves in Ultracold Atomic Collisions}, journal = {Science}, volume = {335}, number = {6066}, year = {2011}, month = {dec}, pages = {314{\textendash}317}, abstract = {Interactions between particles can be strongly altered by their environment. We demonstrate a technique for modifying interactions between ultracold atoms by dressing the bare atomic states with light, creating an effective interaction of vastly increased range that scatters states of finite relative angular momentum at collision energies where only s-wave scattering would normally be expected. We collided two optically dressed neutral atomic Bose-Einstein condensates with equal, and opposite, momenta and observed that the usual s-wave distribution of scattered atoms was altered by the appearance of d- and g-wave contributions. This technique is expected to enable quantum simulation of exotic systems, including those predicted to support Majorana fermions.

}, keywords = {2011, Multiple Fellows}, issn = {1095-9203}, url = {http://www.sciencemag.org/content/335/6066/314.abstract}, author = {Ross A Williams and Lindsay J LeBlanc and Karina Jim{\'e}nez-Garc{\'\i}a and Matthew C Beeler and Abigail R Perry and William D Phillips and Ian B Spielman} } @article {Kim2011b, title = {Thin-film superconducting resonator tunable to the ground-state hyperfine splitting of 87Rb}, journal = {AIP Advances}, volume = {1}, number = {4}, year = {2011}, month = {oct}, pages = {042107}, keywords = {2011, electron beam lithography, ground states, inductance, Multiple Fellows, niobium, superconducting microwave devices, superconducting resonators, superconducting thin films, type II superconductors}, issn = {21583226}, url = {http://link.aip.org/link/?AAIDBI/1/042107/1}, author = {Kim, Z. and Vlahacos, C. P. and Jonathan E Hoffman and Grover, J. A. and Voigt, K. D. and Benjamin K Cooper and Ballard, C. J. and B S Palmer and Mohammad Hafezi and Jacob M Taylor and Jeffrey R Anderson and Dragt, A. J. and Christopher J Lobb and Luis A Orozco and Steven L Rolston and F C Wellstood} } @article {Berninger2011, title = {Universality of the Three-Body Parameter for Efimov States in Ultracold Cesium}, journal = {Phys. Rev. Lett.}, volume = {107}, number = {12}, year = {2011}, month = {sep}, pages = {120401}, keywords = {2011}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v107/i12/e120401}, author = {Martin Berninger and Alessandro Zenesini and Bo Huang and Walter Harm and N{\"a}gerl, H.-C. and Francesca Ferlaino and Rudolf Grimm and Paul S Julienne and Jeremy M Hutson} } @article {Artuso2011, title = {Using local fields to tailor hybrid quantum-dot/metal nanoparticle systems}, journal = {Phys. Rev. B}, volume = {83}, number = {23}, year = {2011}, month = {jun}, pages = {235406}, keywords = {2011}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v83/i23/e235406}, author = {Ryan D Artuso and Garnett W Bryant and Garcia-Etxarri, Aitzol and Javier Aizpurua} } @article {Barnett2010, title = {Antiferromagnetic spinor condensates are quantum rotors}, journal = {Phys. Rev. A}, volume = {82}, number = {3}, year = {2010}, month = {sep}, keywords = {2010, Multiple Fellows}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v82/i3/e031602}, author = {Ryan Barnett and Jay D Sau and S. Das Sarma} } @article {2463, title = {A Blueprint for a Topologically Fault-Tolerant Quantum Computer}, journal = {arXiv}, volume = {1003}, year = {2010}, month = {3/2010}, pages = {2856}, url = {http://arxiv.org/abs/1003.2856}, author = {Parsa Bonderson and S. Das Sarma and Michael Freedman and Chetan Nayak} } @article { ISI:000278150100050, title = {Colossal Magnetoresistance in an Ultraclean Weakly Interacting 2D Fermi Liquid}, journal = {PHYSICAL REVIEW LETTERS}, volume = {104}, number = {21}, year = {2010}, month = {MAY 28}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.104.216801}, author = {Zhou, Xiaoqing and Piot, B. A. and Bonin, M. and Engel, L. W. and S. Das Sarma and Gervais, G. and Pfeiffer, L. N. and West, K. W.} } @article {Bryant2010, title = {Effect of Mechanical Strain on the Optical Properties of Quantum Dots: Controlling Exciton Shape, Orientation, and Phase with a Mechanical Strain}, journal = {Phys. Rev. Lett.}, volume = {105}, number = {6}, year = {2010}, month = {aug}, keywords = {2010}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v105/i6/e067404}, author = {Garnett W Bryant and M Zieli{\'n}ski and Natalia Malkova and Sims, James and W Jask{\'o}lski and Javier Aizpurua} } @article {Barberis-Blostein2010, title = {From quantum feedback to probabilistic error correction: manipulation of quantum beats in cavity QED}, journal = {New J. Phys.}, volume = {12}, number = {2}, year = {2010}, month = {feb}, pages = {023002}, abstract = {It is shown how one can implement quantum feedback and probabilistic error correction in an open quantum system consisting of a single atom, with ground- and excited-state Zeeman structure, in a driven two-mode optical cavity. The ground-state superposition is manipulated and controlled through conditional measurements and external fields, which shield the coherence and correct quantum errors. Modeling an experimentally realistic situation demonstrates the robustness of the proposal for realization in the laboratory.}, keywords = {2010}, issn = {1367-2630}, url = {http://stacks.iop.org/1367-2630/12/i=2/a=023002}, author = {P Barberis-Blostein and Norris, D G and Luis A Orozco and Howard J Carmichael} } @article {Restelli2010, title = {Improved Timing Resolution Single-Photon Detectors in Daytime Free-Space Quantum Key Distribution With 1.25 GHz Transmission Rate}, journal = {Selected Topics in Quantum Electronics, IEEE Journal of}, volume = {16}, number = {5}, year = {2010}, month = {sep}, pages = {1084{\textendash}1090}, abstract = {In free-space single-photon quantum key distribution (QKD), the error rate due to daytime background photons can be reduced with strong temporal filtering. In this case, the improvement in performance is determined by the receiver{\textquoteright}s ability to resolve signal-photon arrival times. We use fast clock recovery and commercially available single-photon detectors with timing resolution enhanced by additional electronic circuitry to implement temporal gating down to 50 ps in a free-space QKD system. The single-photon channel operates at 850 nm, and the improved timing resolution enables transmission rates of 1.25 GHz. We observe daytime quantum bit error rates of 0.04, which is less than one-third of the ungated error rate. We present the design and performance of the system and demonstrate its benefit to free-space QKD.

}, keywords = {2010}, issn = {1077-260X}, url = {http://ieeexplore.ieee.org/xpl/freeabs\_all.jsp?arnumber=5433021}, author = {Restelli, Alessandro and Bienfang, Joshua C. and Charles W Clark and Rech, Ivan and Labanca, Ivan and Ghioni, Massimo and Cova, Sergio} } @article {2548, title = {Interacting Hofstadter Spectrum of Atoms in an Artificial Gauge Field}, journal = {PHYSICAL REVIEW LETTERS}, volume = {104}, year = {2010}, month = {JUN 25}, pages = {255303}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.104.255303}, author = {Powell, Stephen and Ryan Barnett and Sensarma, Rajdeep and S. Das Sarma} } @conference {Pooser2010, title = {Low-noise amplification of a continuous-variable quantum state}, booktitle = {Proceedings of the SPIE}, volume = {7702}, number = {1}, year = {2010}, month = {apr}, pages = {77020O{\textendash}77020O{\textendash}11}, keywords = {2010, Multiple JQI Affil., Single Fellow}, issn = {0277786X}, url = {http://link.aip.org/link/?PSISDG/7702/77020O/1}, author = {Raphael C Pooser and Alberto M Marino and Vincent Boyer and Kevin M Jones and Paul D Lett} } @article {Ropp2010, title = {Manipulating quantum dots to nanometer precision by control of flow}, journal = {Nano Lett.}, volume = {10}, number = {7}, year = {2010}, month = {jul}, pages = {2525{\textendash}30}, publisher = {American Chemical Society}, abstract = {We present a method for manipulating preselected quantum dots (QDs) with nanometer precision by flow control. The accuracy of this approach scales more favorably with particle size than optical trapping, enabling more precise positioning of nanoscopic particles. We demonstrate the ability to position a single QD in a 100 microm working region to 45 nm accuracy for holding times exceeding one hour and the ability to take active quantum measurements on the dynamically manipulated QD.

}, keywords = {2010, Single Fellow}, issn = {1530-6992}, url = {http://dx.doi.org/10.1021/nl101105j}, author = {Ropp, Chad and Probst, Roland and Cummins, Zachary and Kumar, Rakesh and Berglund, Andrew J and Raghavan, Srinivasa R and Edo Waks and Shapiro, Benjamin} } @article {Carr2010, title = {Mesoscopic effects in quantum phases of ultracold quantum gases in optical lattices}, journal = {Phys. Rev. A}, volume = {81}, number = {1}, year = {2010}, month = {jan}, keywords = {2010, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v81/i1/e013613}, author = {L D Carr and Wall, M. L. and Schirmer, D. G. and Roger C Brown and James E Williams and Charles W Clark} } @article {Becerra2010, title = {Nondegenerate four-wave mixing in rubidium vapor: Transient regime}, journal = {Phys. Rev. A}, volume = {82}, number = {4}, year = {2010}, month = {oct}, keywords = {2010}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v82/i4/e043833}, author = {Francisco E Becerra and R T Willis and Steven L Rolston and Howard J Carmichael and Luis A Orozco} } @article {Behunin2010, title = {Nonequilibrium Casimir{\textendash}Polder force in non-stationary systems}, journal = {J. Phys. A: Math. Theor.}, volume = {43}, number = {1}, year = {2010}, month = {jan}, pages = {012001}, abstract = {Recently the Casimir{\textendash}Polder force felt by an atom near a substrate under nonequilibrium stationary conditions has been studied theoretically with macroscopic quantum electrodyanamics (MQED) and verified experimentally with cold atoms. We give a quantum field theory derivation of the Langevin equation describing the atom{\textquoteright}s motion based on the influence functional method valid for fully nonequilibrium (nonstationary) conditions. The noise associated with the quantum field derived from first principles is generally colored and nonlocal, which is at variance with the {\textquoteright}local source hypothesis{\textquoteright} of MQED{\textquoteright}s generalization to nonequilibrium conditions. Precision measurements on the shape deformation of an atomic gas as a function of its distance from a mirror would provide a direct check of our predictions based on the Langevin equation.

}, keywords = {2010}, issn = {1751-8113}, url = {http://stacks.iop.org/1751-8121/43/i=1/a=012001}, author = {Ryan O Behunin and Bei-Lok Hu} } @article {Behunin2010a, title = {Nonequilibrium forces between neutral atoms mediated by a quantum field}, journal = {Phys. Rev. A}, volume = {82}, number = {2}, year = {2010}, month = {aug}, keywords = {2010}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v82/i2/e022507}, author = {Ryan O Behunin and Bei-Lok Hu} } @article {Zou2010, title = {Particle-hole symmetric localization in optical lattices using time modulated random on-site potentials}, journal = {Phys. Rev. B}, volume = {82}, number = {22}, year = {2010}, month = {dec}, keywords = {2010, No Fellows}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v82/i22/e224205}, author = {Zou, Yue and Ryan Barnett and Refael, Gil} } @article {Biddle2010, title = {Predicted Mobility Edges in One-Dimensional Incommensurate Optical Lattices: An Exactly Solvable Model of Anderson Localization}, journal = {Phys. Rev. Lett.}, volume = {104}, number = {7}, year = {2010}, month = {feb}, pages = {070601}, keywords = {2010, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v104/i7/e070601}, author = {J Biddle and S. Das Sarma} } @article {Ospelkaus2010, title = {Quantum-state controlled chemical reactions of ultracold potassium-rubidium molecules}, journal = {Science}, volume = {327}, number = {5967}, year = {2010}, month = {feb}, pages = {853{\textendash}7}, abstract = {How does a chemical reaction proceed at ultralow temperatures? Can simple quantum mechanical rules such as quantum statistics, single partial-wave scattering, and quantum threshold laws provide a clear understanding of the molecular reactivity under a vanishing collision energy? Starting with an optically trapped near-quantum-degenerate gas of polar 40K87Rb molecules prepared in their absolute ground state, we report experimental evidence for exothermic atom-exchange chemical reactions. When these fermionic molecules were prepared in a single quantum state at a temperature of a few hundred nanokelvin, we observed p-wave-dominated quantum threshold collisions arising from tunneling through an angular momentum barrier followed by a short-range chemical reaction with a probability near unity. When these molecules were prepared in two different internal states or when molecules and atoms were brought together, the reaction rates were enhanced by a factor of 10 to 100 as a result of s-wave scattering, which does not have a centrifugal barrier. The measured rates agree with predicted universal loss rates related to the two-body van der Waals length.}, keywords = {2010}, issn = {1095-9203}, url = {http://www.sciencemag.org/content/327/5967/853.abstract}, author = {Ospelkaus, S. and Ni, K.-K. and Wang, D. and de Miranda, M. H. G. and B Neyenhuis and Qu{\'e}m{\'e}ner, G and Paul S Julienne and Bohn, J L and D S Jin and Jun Ye} } @article {Pironio2010, title = {Random numbers certified by Bell{\textquoteright}s theorem}, journal = {Nature}, volume = {464}, number = {7291}, year = {2010}, month = {apr}, pages = {1021{\textendash}4}, publisher = {Macmillan Publishers Limited. All rights reserved}, abstract = {Randomness is a fundamental feature of nature and a valuable resource for applications ranging from cryptography and gambling to numerical simulation of physical and biological systems. Random numbers, however, are difficult to characterize mathematically, and their generation must rely on an unpredictable physical process. Inaccuracies in the theoretical modelling of such processes or failures of the devices, possibly due to adversarial attacks, limit the reliability of random number generators in ways that are difficult to control and detect. Here, inspired by earlier work on non-locality-based and device-independent quantum information processing, we show that the non-local correlations of entangled quantum particles can be used to certify the presence of genuine randomness. It is thereby possible to design a cryptographically secure random number generator that does not require any assumption about the internal working of the device. Such a strong form of randomness generation is impossible classically and possible in quantum systems only if certified by a Bell inequality violation. We carry out a proof-of-concept demonstration of this proposal in a system of two entangled atoms separated by approximately one metre. The observed Bell inequality violation, featuring near perfect detection efficiency, guarantees that 42 new random numbers are generated with 99 per cent confidence. Our results lay the groundwork for future device-independent quantum information experiments and for addressing fundamental issues raised by the intrinsic randomness of quantum theory.}, keywords = {2010, Single Fellow}, issn = {1476-4687}, url = {http://dx.doi.org/10.1038/nature09008 http://arxiv.org/abs/0911.3427}, author = {Pironio, S and A Ac{\'\i}n and Massar, S and A Boyer de la Giroday and D N Matsukevich and P Maunz and Steven Olmschenk and David Hayes and L Luo and T A Manning and Christopher Monroe} } @article {2550, title = {Realistic Time-Reversal Invariant Topological Insulators with Neutral Atoms}, journal = {PHYSICAL REVIEW LETTERS}, volume = {105}, year = {2010}, month = {DEC 16}, pages = {255302}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.105.255302}, author = {N. Goldman and Satija, I. and Nikolic, P. and Bermudez, A. and Martin-Delgado, M. A. and Lewenstein, M. and Ian B Spielman} } @article {Levine2010a, title = {RECIST versus volume measurement in medical CT using ellipsoids of known size}, journal = {Optics Express}, volume = {18}, number = {8}, year = {2010}, month = {apr}, pages = {8151}, publisher = {OSA}, abstract = {Two hundred eighty three uniaxial ellipsoids with sizes from 4 mm to 11 mm were measured with a coordinate measuring matching (CMM) and also scanned using a medical computed tomography (CT) machine. Their volumes were determined by counting voxels over a threshold, as well as using equivalent volumes from the length given by the RECIST 1.1 criterion (Response Evaluation Criteria in Solid Tumors). The volumetric measurements yield an order of magnitude reduction in residuals compared to the CMM measurements than the residuals of the RECIST measurements also compared to the CMM measurements.}, keywords = {2010, Medical optics instrumentation, X-ray imaging}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-18-8-8151}, author = {Zachary H Levine and Borchardt, Bruce R. and Brandenburg, Nolan J. and Charles W Clark and Muralikrishnan, Bala and Shakarji, Craig M. and Chen, Joseph J. and Siegel, Eliot L.} } @article { ISI:000276248900028, title = {Signatures of Klein tunneling in disordered graphene p-n-p junctions}, journal = {PHYSICAL REVIEW B}, volume = {81}, number = {12}, year = {2010}, month = {MAR}, issn = {1098-0121}, doi = {10.1103/PhysRevB.81.121408}, author = {Rossi, E. and Bardarson, J. H. and Brouwer, P. W. and S. Das Sarma} } @article {Borjemscaia2010, title = {Single-photon propagation through dielectric bandgaps}, journal = {Optics Express}, volume = {18}, number = {3}, year = {2010}, month = {jan}, pages = {2279}, publisher = {OSA}, abstract = {Theoretical models of photon traversal through quarter-wave dielectric stack barriers that arise due to Bragg reflection predict the saturation of the propagation time with the barrier length, known as the Hartman effect. This saturation is sensitive to the addition of single dielectric layers, varying significantly from sub-luminal to apparently super-luminal and vice versa. Our research tests the suitability of photonic bandgaps as an optical model for the tunneling process. Of particular importance is our observation of subtle structural changes in dielectric stacks drastically affecting photon traversal times, allowing for apparent sub- and super-luminal effects. We also introduce a simple model to link HOM visibility to wavepacket distortion that allows us to exclude this as a possible cause of the loss of contrast in the barrier penetration process.

}, keywords = {2010, Physical optics, Tunneling}, issn = {1094-4087}, doi = {10.1364/OE.18.002279}, author = {Borjemscaia, Natalia and Sergey V Polyakov and Paul D Lett and Alan L Migdall} } @article {Bell2010, title = {A slow atom source using a collimated effusive oven and a single-layer variable pitch coil Zeeman slower}, journal = {Rev. Sci. Instrum.}, volume = {81}, number = {1}, year = {2010}, month = {jan}, pages = {013105}, abstract = {We describe a simple slow atom source for loading a rubidium magneto-optical trap. The source includes an effusive oven with a long heated collimation tube. Almost all components are standard vacuum parts. The heating elements and thermocouples are external to the vacuum, protecting them from the hostile hot alkali environment and allowing repair without breaking vacuum. The thermal source is followed by a Zeeman slower with a single-layer coil of variable winding pitch. The single-layer design is simple to construct and has low inductance which allows for rapid switching of the magnetic field. The coil pitch was determined by fitting the analytic form of the magnetic field for a variable winding pitch to the desired magnetic field profile required to slow atoms. The measured magnetic field for the constructed coil is in excellent agreement with the desired field. The source produces atoms at 35 m/s with a flux up to 2 x 10(10) cm(-2) s(-1) at 200 degrees C.}, keywords = {2010, magnetic fields, magnetic traps, magneto-optical effects, rubidium, thermocouples}, issn = {1089-7623}, url = {http://link.aip.org/link/?RSINAK/81/013105/1}, author = {Bell, S. C. and Junker, M. and Jasperse, M. and L D Turner and Y -J Lin and Ian B Spielman and Scholten, R. E.} } @article {Pupillo2010, title = {Strongly Correlated Gases of Rydberg-Dressed Atoms: Quantum and Classical Dynamics}, journal = {Phys. Rev. Lett.}, volume = {104}, number = {22}, year = {2010}, month = {jun}, keywords = {2010, Multiple JQI Affil., No Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v104/i22/e223002}, author = {Guido Pupillo and Micheli, A. and Boninsegni, M. and Lesanovsky, I. and Peter Zoller} } @article {Artuso2010, title = {Strongly coupled quantum dot-metal nanoparticle systems: Exciton-induced transparency, discontinuous response, and suppression as driven quantum oscillator effects}, journal = {Phys. Rev. B}, volume = {82}, number = {19}, year = {2010}, month = {nov}, keywords = {2010}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v82/i19/e195419}, author = {Ryan D Artuso and Garnett W Bryant} } @article {Barnett2010a, title = {Vortex synchronization in Bose{\textendash}Einstein condensates: a time-dependent Gross{\textendash}Pitaevskii equation approach}, journal = {New J. Phys.}, volume = {12}, number = {4}, year = {2010}, month = {apr}, pages = {043004}, abstract = {In this work, we consider vortex lattices in rotating Bose{\textendash}Einstein condensates composed of two species of bosons having different masses. Previously (Barnett et al 2008 New J. Phys. 10 043030), it was claimed that the vortices of the two species form bound pairs and the two vortex lattices lock. Remarkably, the two condensates and the external drive all rotate at different speeds owing to the disparity of the masses of the constituent bosons. In this paper, we study the system by solving the full two-component Gross{\textendash}Pitaevskii equations numerically. Using this approach, we verify the stability of the putative locked state that is found to exist within a disc centered on the axis of rotation and that depends on the mass ratio of the two bosons. We also derive a refined estimate for the locking radius tailored to the experimentally relevant case of a harmonic trap and show that this agrees with the numerical results. Finally, we analyze in detail the rotation rates of the different components in the locked and unlocked regimes.}, keywords = {2010}, issn = {1367-2630}, url = {http://stacks.iop.org/1367-2630/12/i=4/a=043004}, author = {Ryan Barnett and Chen, Edward and Refael, Gil} } @article {Junkermeier2009, title = {Amorphous nature of small CdS nanoparticles: Molecular dynamics simulations}, journal = {Phys. Rev. B}, volume = {79}, number = {12}, year = {2009}, month = {mar}, keywords = {2009}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v79/i12/e125323}, author = {Junkermeier, Chad and Lewis, James and Garnett W Bryant} } @article {Adam2009, title = {Crossover from quantum to Boltzmann transport in graphene}, journal = {Phys. Rev. B}, volume = {79}, number = {20}, year = {2009}, month = {may}, keywords = {2009, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v79/i20/e201404}, author = {Shaffique Adam and Brouwer, Piet and S. Das Sarma} } @article {Leibrandt2009, title = {Demonstration of a scalable, multiplexed ion trap for quantum information processing}, year = {2009}, month = {apr}, pages = {18}, abstract = {A scalable, multiplexed ion trap for quantum information processing is fabricated and tested. The trap design and fabrication process are optimized for scalability to small trap size and large numbers of interconnected traps, and for integration of control electronics and optics. Multiple traps with similar designs are tested with Cd+, Mg+, and Sr+ ions at room temperature and with Sr+ at 6 K, with respective ion lifetimes of 90 s, 300 +/- 30 s, 56 +/- 6 s, and 4.5 +/- 1.1 hours. The motional heating rate for Mg+ at room temperature and a trap frequency of 1.6 MHz is measured to be 7 +/- 3 quanta per millisecond. For Sr+ at 6 K and 540 kHz the heating rate is measured to be 220 +/- 30 quanta per second.}, keywords = {2009}, url = {http://arxiv.org/abs/0904.2599}, author = {Leibrandt, D. R. and Labaziewicz, J. and R J Clark and Chuang, I. L. and Epstein, R. J. and Ospelkaus, C. and Wesenberg, J. H. and Bollinger, J. J. and Leibfried, D. and David J Wineland and Stick, D. and J D Sterk and Christopher Monroe and Pai, C. -S. and Low, Y. and Frahm, R. and Slusher, R. E.} } @article {Boyer2009, title = {Entangling light in its spatial degrees of freedom with four-wave mixing in an atomic vapor}, journal = {Chemphyschem}, volume = {10}, number = {5}, year = {2009}, month = {mar}, pages = {755{\textendash}60}, abstract = {The entanglement properties of two beams of light can reside in subtle correlations that exist in the unavoidable quantum fluctuations of their amplitudes and phases. Recent advances in the generation of nonclassical light with four-wave mixing in an atomic vapor have permitted the production and the observation of entanglement that is localized in almost arbitrary transverse regions of a pair of beams. These multi-spatial-mode entangled beams may prove useful for an array of applications ranging from noise-free imaging and improved position sensing to quantum information processing.}, keywords = {2009}, issn = {1439-7641}, url = {http://www.ncbi.nlm.nih.gov/pubmed/19226507}, author = {Vincent Boyer and Alberto M Marino and Raphael C Pooser and Paul D Lett} } @article { ISI:000263815400088, title = {Fluctuation-induced first-order transition in p-wave superconductors}, journal = {PHYSICAL REVIEW B}, volume = {79}, number = {5}, year = {2009}, month = {FEB}, issn = {1098-0121}, doi = {10.1103/PhysRevB.79.054514}, author = {Li, Qi and Belitz, D. and Toner, John} } @article {Willis2009, title = {Four-wave mixing in the diamond configuration in an atomic vapor}, journal = {Phys. Rev. A}, volume = {79}, number = {3}, year = {2009}, month = {mar}, keywords = {2009}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v79/i3/e033814}, author = {R T Willis and Francisco E Becerra and Luis A Orozco and Steven L Rolston} } @article {G.Brida2009, title = {Improved implementation and modeling of deadtime reduction in an actively multiplexed detection system}, journal = {Journal of Modern Optics}, volume = {56}, year = {2009}, pages = {405{\textendash}412}, keywords = {2009}, author = {Giorgio Brida and Ivo P Degiovanni and Valentina Schettini and Sergey V Polyakov and Alan L Migdall} } @article {Brida2009a, title = {Improved implementation of the Alicki{\textendash}Van Ryn nonclassicality test for a single particle using Si detectors}, journal = {Phys. Rev. A}, volume = {79}, number = {4}, year = {2009}, month = {apr}, keywords = {2009}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v79/i4/e044102}, author = {Giorgio Brida and Ivo P Degiovanni and Marco Genovese and Fabrizio Piacentini and Valentina Schettini and Gisin, Nicolas and Sergey V Polyakov and Alan L Migdall} } @article {Borkowski2009, title = {Line shapes of optical Feshbach resonances near the intercombination transition of bosonic Ytterbium}, year = {2009}, month = {may}, abstract = {The properties of bosonic Ytterbium photoassociation spectra near the intercombination transition \$\^{}\{1\}S\_\{0\}\${\textendash}\$\^{}\{3\}P\_\{1\}\$ are studied theoretically at ultra low temperatures. We demonstrate how the shapes and intensities of rotational components of optical Feshbach resonances are affected by mass tuning of the scattering properties of the two colliding ground state atoms. Particular attention is given to the relationship between the magnitude of the scattering length and the occurrence of shape resonances in higher partial waves of the van der Waals system. We develop a mass scaled model of the excited state potential that represents the experimental data for different isotopes. The shape of the rotational photoassociation spectrum for various bosonic Yb isotopes can be qualitatively different.}, keywords = {2009}, url = {http://arxiv.org/abs/0905.0958}, author = {Mateusz Borkowski and Roman Ciurylo and Paul S Julienne and Tojo, S. and Katsunari Enomoto and Yoshiro Takahashi} } @article {Biddle2009, title = {Localization in one-dimensional incommensurate lattices beyond the Aubry-Andr{\'e} model}, journal = {Phys. Rev. A}, volume = {80}, number = {2}, year = {2009}, month = {aug}, keywords = {2009, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v80/i2/e021603}, author = {J Biddle and Bin Wang and Priour, D. and S. Das Sarma} } @article {Wu2009, title = {A multi-photon magneto-optical trap}, year = {2009}, month = {sep}, pages = {10}, abstract = {We demonstrate a Magneto-Optical Trap (MOT) configuration which employs optical forces due to light scattering between electronically excited states of the atom. With the standard MOT laser beams propagating along the \{$\backslash$it x\}- and \{$\backslash$it y\}- directions, the laser beams along the \{$\backslash$it z\}-direction are at a different wavelength that couples two sets of \{$\backslash$it excited\} states. We demonstrate efficient cooling and trapping of cesium atoms in a vapor cell and sub-Doppler cooling on both the red and blue sides of the two-photon resonance. The technique demonstrated in this work may have applications in background-free detection of trapped atoms, and in assisting laser-cooling and trapping of certain atomic species that require cooling lasers at inconvenient wavelengths.}, keywords = {2009}, url = {http://arxiv.org/abs/0909.1949}, author = {Wu, Saijun and Plisson, Thomas and Roger C Brown and William D Phillips and J V Porto} } @article {Malkova2009a, title = {Observation of optical Shockley-like surface states in photonic superlattices}, journal = {Optics Letters}, volume = {34}, number = {11}, year = {2009}, month = {may}, pages = {1633}, publisher = {OSA}, abstract = {We provide what we believe to be the first experimental demonstration of linear Shockley-like surface states in an optically induced semi-infinite photonic superlattice. Such surface states appear only when the induced superlattice consisting of alternating strong and weak bonds is terminated properly at the surface. Our experimental results are in good agreement with our theoretical analysis.}, keywords = {2009, integrated optics, Nonlinear optics, Nonlinear optics at surfaces, Pulse propagation and temporal solitons, transverse effects in}, issn = {0146-9592}, url = {http://ol.osa.org/abstract.cfm?URI=ol-34-11-1633}, author = {Natalia Malkova and Hromada, Ivan and Wang, Xiaosheng and Garnett W Bryant and Chen, Zhigang} } @article {Balakrishnan2009, title = {Particle-Hole Asymmetry and Brightening of Solitons in a Strongly Repulsive Bose-Einstein Condensate}, journal = {Phys. Rev. Lett.}, volume = {103}, number = {23}, year = {2009}, month = {12/2009}, keywords = {2009}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.103.230403}, author = {Balakrishnan, Radha and Indubala Satija and Charles W Clark} } @article {Campbell2009, title = {Probing interactions between ultracold fermions}, journal = {Science}, volume = {324}, number = {5925}, year = {2009}, month = {apr}, pages = {360{\textendash}3}, abstract = {At ultracold temperatures, the Pauli exclusion principle suppresses collisions between identical fermions. This has motivated the development of atomic clocks with fermionic isotopes. However, by probing an optical clock transition with thousands of lattice-confined, ultracold fermionic strontium atoms, we observed density-dependent collisional frequency shifts. These collision effects were measured systematically and are supported by a theoretical description attributing them to inhomogeneities in the probe excitation process that render the atoms distinguishable. This work also yields insights for zeroing the clock density shift.

}, keywords = {2009}, issn = {1095-9203}, url = {http://www.sciencemag.org/content/324/5925/360.abstract}, author = {Gretchen K Campbell and Boyd, M. M. and J W Thomsen and Martin, M J and Blatt, S and Swallows, M D and T L Nicholson and Fortier, T and Oates, C W and Diddams, S A and Lemke, N D and Pascal Naidon and Paul S Julienne and Jun Ye and Ludlow, A. D.} } @article {Pooser2009, title = {Quantum correlated light beams from non-degenerate four-wave mixing in an atomic vapor: the D1 and D2 lines of \^85Rb and \^87Rb}, journal = {Optics Express}, volume = {17}, number = {19}, year = {2009}, month = {sep}, pages = {16722}, publisher = {OSA}, abstract = {We present experimental results showing that quantum correlated light can be produced using non-degenerate, off-resonant, four-wave mixing (4WM) on both the D1 (795 nm) and D2 (780 nm) lines of 85Rb and 87Rb, extending earlier work on the D1 line of 85Rb. Using this 4WM process in a hot vapor cell to produce bright twin beams, we characterize the degree of intensity-difference noise reduction below the standard quantum limit for each of the four systems. Although each system approximates a double-lambda configuration, differences in details of the actual level structure lead to varying degrees of noise reduction. The observation of quantum correlations on light produced using all four of these systems, regardless of their substructure, suggests that it should be possible to use other systems with similar level structures in order to produce narrow frequency, non-classical beams at a particular wavelength.}, keywords = {2009, Nonlinear optical devices, Squeezed states}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-17-19-16722}, author = {Raphael C Pooser and Alberto M Marino and Vincent Boyer and Kevin M Jones and Paul D Lett} } @article { ISI:000270383200044, title = {Robust pairing mechanism from repulsive interactions}, journal = {PHYSICAL REVIEW B}, volume = {80}, number = {11}, year = {2009}, month = {SEP}, issn = {1098-0121}, doi = {10.1103/PhysRevB.80.115116}, author = {Al-Hassanieh, K. A. and Batista, C. D. and Sengupta, P. and Feiguin, A. E.} } @article {Brida2009, title = {Scalable multiplexed detector system for high-rate telecom-band single-photon detection}, journal = {Rev. Sci. Instrum.}, volume = {80}, number = {11}, year = {2009}, month = {nov}, pages = {116103}, abstract = {We present an actively multiplexed photon-counting detection system at telecom wavelengths that overcomes the difficulties of photon-counting at high rates. We find that for gated detectors, the heretofore unconsidered deadtime associated with the detector gate is a critical parameter, that limits the overall scalability of the scheme to just a few detectors. We propose and implement a new scheme that overcomes this problem and restores full scalability that allows an order of magnitude improvement with systems with as few as 4 detectors. When using just two multiplexed detectors, our experimental results show a 5x improvement over a single detector and a greater than 2x improvement over multiplexed schemes that do not consider gate deadtime.}, keywords = {2009, infrared detectors, multiplexing, optical receivers, photodetectors, Photon counting, quantum communication, Quantum optics}, issn = {1089-7623}, url = {http://link.aip.org/link/?RSINAK/80/116103/1}, author = {Giorgio Brida and Ivo P Degiovanni and Fabrizio Piacentini and Valentina Schettini and Sergey V Polyakov and Alan L Migdall} } @article { ISI:000262977900105, title = {Skyrmion versus vortex flux lattices in p-wave superconductors}, journal = {PHYSICAL REVIEW B}, volume = {79}, number = {1}, year = {2009}, month = {JAN}, issn = {1098-0121}, doi = {10.1103/PhysRevB.79.014517}, author = {Li, Qi and Toner, John and Belitz, D.} } @article {2461, title = {State diagrams for harmonically trapped bosons in optical lattices}, journal = {Phys. Rev. A}, volume = {79}, year = {2009}, month = {5/2009}, pages = {053605}, doi = {10.1103/PhysRevA.79.053605}, author = {Rigol, Marcos and George G. Batrouni and Valery G. Rousseau and Richard T. Scalettar} } @article {Satija2009, title = {Symmetry-breaking and symmetry-restoring dynamics of a mixture of Bose-Einstein condensates in a double well}, journal = {Phys. Rev. A}, volume = {79}, number = {3}, year = {2009}, month = {mar}, pages = {033616}, abstract = {We study the coherent nonlinear tunneling dynamics of a binary mixture of Bose-Einstein condensates in a double-well potential. We demonstrate the existence of a new type of mode associated with the "swapping" of the two species in the two wells of the potential. In contrast to the symmetry breaking macroscopic quantum self-trapping (MQST) solutions, the swapping modes correspond to the tunneling dynamics that preserves the symmetry of the double well potential. As a consequence of two distinct types of broken symmetry MQST phases where the two species localize in the different potential welils or coexist in the same well, the corresponding symmetry restoring swapping modes result in dynamics where the the two species either avoid or chase each other. In view of the possibility to control the interaction between the species, the binary mixture offers a very robust system to observe these novel effects as well as the phenomena of Josephson oscillations and pi-modes

}, keywords = {2009, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v79/i3/e033616 }, author = {Indubala Satija and Balakrishnan, Radha and Naudus, Phillip and Heward, Jeffrey and Edwards, Mark and Charles W Clark} } @article {Hormozi2009, title = {Topological Quantum Computing with Read-Rezayi States}, journal = {Phys. Rev. Lett.}, volume = {103}, number = {16}, year = {2009}, month = {oct}, keywords = {2009}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v103/i16/e160501}, author = {Hormozi, L. and Bonesteel, N. and Simon, S.} } @article {Malkova2009, title = {Transition between Tamm-like and Shockley-like surface states in optically induced photonic superlattices}, journal = {Phys. Rev. A}, volume = {80}, number = {4}, year = {2009}, month = {oct}, keywords = {2009}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v80/i4/e043806}, author = {Natalia Malkova and Hromada, Ivan and Wang, Xiaosheng and Garnett W Bryant and Chen, Zhigang} } @article { ISI:000264183000007, title = {Transport through quantum dots: a combined DMRG and embedded-cluster approximation study}, journal = {EUROPEAN PHYSICAL JOURNAL B}, volume = {67}, number = {4}, year = {2009}, month = {FEB}, pages = {527-542}, issn = {1434-6028}, doi = {10.1140/epjb/e2009-00036-4}, author = {Heidrich-Meisner, F. and Martins, G. B. and Buesser, C. A. and Al-Hassanieh, K. A. and Feiguin, A. E. and Chiappe, G. and Anda, E. V. and Dagotto, E.} } @article {Marino2009, title = {Tunable delay of Einstein-Podolsky-Rosen entanglement}, journal = {Nature}, volume = {457}, number = {7231}, year = {2009}, month = {feb}, pages = {859{\textendash}62}, publisher = {Macmillan Publishers Limited. All rights reserved}, abstract = {Entangled systems display correlations that are stronger than can be obtained classically. This makes entanglement an essential resource for a number of applications, such as quantum information processing, quantum computing and quantum communications. The ability to control the transfer of entanglement between different locations will play a key role in these quantum protocols and enable quantum networks. Such a transfer requires a system that can delay quantum correlations without significant degradation, effectively acting as a short-term quantum memory. An important benchmark for such systems is the ability to delay Einstein-Podolsky-Rosen (EPR) levels of entanglement and to be able to tune the delay. EPR entanglement is the basis for a number of quantum protocols, allowing the remote inference of the properties of one system (to better than its standard quantum limit) through measurements on the other correlated system. Here we show that a four-wave mixing process based on a double-lambda scheme in hot (85)Rb vapour allows us to obtain an optically tunable delay for EPR entangled beams of light. A significant maximum delay, of the order of the width of the cross-correlation function, is achieved. The four-wave mixing also preserves the quantum spatial correlations of the entangled beams. We take advantage of this property to delay entangled images, making this the first step towards a quantum memory for images.}, keywords = {2009}, issn = {1476-4687}, url = {http://dx.doi.org/10.1038/nature07751}, author = {Alberto M Marino and Raphael C Pooser and Vincent Boyer and Paul D Lett} } @article {Becerra2009, title = {Two-photon dichroic atomic vapor laser lock using electromagnetically induced transparency and absorption}, journal = {JOSA B}, volume = {26}, number = {7}, year = {2009}, month = {jun}, pages = {1315}, publisher = {OSA}, abstract = {We demonstrate a technique to lock the frequency of a laser to a transition between two excited states in Rb vapor using a two-photon process in the presence of a weak magnetic field. We use a ladder configuration from specific hyperfine sublevels of the 5S1/2, 5P3/2, and 5D5/2 levels. This atomic configuration can show electromagnetically induced transparency and absorption processes. The error signal comes from the difference in the transparency or absorption felt by the two orthogonal polarizations of the probe beam. A simplified model is in good quantitative agreement with the observed signals for the experimental parameters. We have used this technique to lock the frequency of the laser up to 1.5 GHz off atomic resonance.}, keywords = {2009, Absorption, Coherent optical effects, Laser stabilization, Zeeman effect}, issn = {0740-3224}, url = {http://josab.osa.org/abstract.cfm?URI=josab-26-7-1315}, author = {Francisco E Becerra and R T Willis and Steven L Rolston and Luis A Orozco} } @article {2470, title = {Adiabaticity and Localization in One-Dimensional Incommensurate Lattices}, journal = {Phys. Rev. Lett.}, volume = {101}, year = {2008}, month = {12/2008}, pages = {260402}, doi = {10.1103/PhysRevLett.101.260402}, author = {Emily E Edwards and Matthew C Beeler and Hong, T and Steven L Rolston} } @article {Lundblad2008, title = {Atoms in a Radio-Frequency-Dressed Optical Lattice}, journal = {Phys. Rev. Lett.}, volume = {100}, number = {15}, year = {2008}, month = {apr}, keywords = {2008, Multiple Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v100/i15/e150401}, author = {Lundblad, N. and Patricia J Lee and Ian B Spielman and Benjamin L Brown and William D Phillips and J V Porto} } @article {Lang2008, title = {Cruising through molecular bound-state manifolds with radiofrequency}, journal = {Nat. Phys.}, volume = {4}, number = {3}, year = {2008}, month = {jan}, pages = {223{\textendash}226}, publisher = {Nature Publishing Group}, abstract = {The production of ultracold molecules with their rich internal structure is currently attracting considerable interest1, 2, 3, 4. For future experiments, it will be important to efficiently transfer these molecules from their initial internal quantum state at production to other quantum states of interest. Transfer tools such as optical Raman schemes5, 6, radiofrequency transitions (see, for example, ref.~7) or magnetic field ramping8, 9 exist, but are either technically involved or limited in their applicability. Here, we demonstrate a simple, highly efficient hybrid transfer method that overcomes a number of the previous limitations. The scheme is based on magnetically tuned mixing of two neighbouring molecular levels, which enables otherwise forbidden radiofrequency transitions between them. By repeating this process at various magnetic fields, molecules can be successively transported through a large manifold of quantum states. Applying nine transfers, we convert very weakly bound Feshbach molecules to a much more deeply bound level with a binding energy corresponding to 3.6~GHz. As an important spin-off of our experiments, we demonstrate a high-precision spectroscopy method for investigating level crossings.}, keywords = {2008, Single Fellow}, issn = {1745-2473}, url = {http://dx.doi.org/10.1038/nphys838}, author = {Lang, F. and Straten, P. v. d. and Brandst{\"a}tter, B. and Thalhammer, G. and Winkler, K. and Paul S Julienne and Rudolf Grimm and J Hecker Denschlag} } @article {Marino2008a, title = {Delocalized Correlations in Twin Light Beams with Orbital Angular Momentum}, journal = {Phys. Rev. Lett.}, volume = {101}, number = {9}, year = {2008}, month = {aug}, keywords = {2008, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v101/i9/e093602}, author = {Alberto M Marino and Vincent Boyer and Raphael C Pooser and Paul D Lett and Lemons, K. and Kevin M Jones} } @article {DeMille2008, title = {Enhanced Sensitivity to Variation of me/mp in Molecular Spectra}, journal = {Phys. Rev. Lett.}, volume = {100}, number = {4}, year = {2008}, month = {jan}, keywords = {2008, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v100/i4/e043202}, author = {DeMille, D and Sainis, S and Sage, J and Bergeman, T and Svetlana Kotochigova and Eite Tiesinga} } @article {Boyer2008a, title = {Entangled images from four-wave mixing}, journal = {Science}, volume = {321}, number = {5888}, year = {2008}, month = {jul}, pages = {544{\textendash}7}, abstract = {Two beams of light can be quantum mechanically entangled through correlations of their phase and intensity fluctuations. For a pair of spatially extended image-carrying light fields, the concept of entanglement can be applied not only to the entire images but also to their smaller details. We used a spatially multimode amplifier based on four-wave mixing in a hot vapor to produce twin images that exhibit localized entanglement. The images can be bright fields that display position-dependent quantum noise reduction in their intensity difference or vacuum twin beams that are strongly entangled when projected onto a large range of different spatial modes. The high degree of spatial entanglement demonstrates that the system is an ideal source for parallel continuous-variable quantum information protocols.}, keywords = {2008, Single Fellow}, issn = {1095-9203}, url = {http://www.sciencemag.org/content/321/5888/544.abstract}, author = {Vincent Boyer and Alberto M Marino and Raphael C Pooser and Paul D Lett} } @article {Brida2008, title = {Experimental test of nonclassicality for a single particle}, journal = {Optics Express}, volume = {16}, number = {16}, year = {2008}, month = {jul}, pages = {11750}, abstract = {In a recent paper [R. Alicki and N. Van Ryn, J. Phys. A: Math. Theor., 41, 062001 (2008)] a test of nonclassicality for a single qubit was proposed. Here, we discuss the class of local realistic theories to which this test applies and present an experimental realization.}, keywords = {2008, Single Fellow}, issn = {1094-4087}, url = {http://arxiv.org/abs/0804.1646}, author = {Giorgio Brida and Ivo P Degiovanni and Marco Genovese and Valentina Schettini and Sergey V Polyakov and Alan L Migdall} } @article {Boyer2008, title = {Generation of Spatially Broadband Twin Beams for Quantum Imaging}, journal = {Phys. Rev. Lett.}, volume = {100}, number = {14}, year = {2008}, month = {apr}, keywords = {2008, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v100/i14/e143601}, author = {Vincent Boyer and Alberto M Marino and Paul D Lett} } @article {Pelton2008, title = {Metal-nanoparticle plasmonics}, journal = {Laser \& Photon. Rev.}, volume = {2}, number = {3}, year = {2008}, month = {jul}, pages = {136{\textendash}159}, keywords = {2008, Single Fellow}, issn = {18638880}, url = {http://doi.wiley.com/10.1002/lpor.200810003}, author = {Matthew Pelton and Javier Aizpurua and Garnett W Bryant} } @conference {Polyakov2008, title = {Multiplexed photon-counting detectors}, booktitle = {Proceedings of the SPIE}, volume = {6900}, year = {2008}, month = {jan}, pages = {690019{\textendash}690019{\textendash}8}, publisher = {SPIE}, organization = {SPIE}, keywords = {2008, Single Fellow}, issn = {0277786X}, url = {http://adsabs.harvard.edu/abs/2008SPIE.6900E..26P}, author = {Sergey V Polyakov and Valentina Schettini and Ivo P Degiovanni and Giorgio Brida and Alan L Migdall} } @article {Becerra2008, title = {Nondegenerate four-wave mixing in rubidium vapor: The diamond configuration}, journal = {Phys. Rev. A}, volume = {78}, number = {1}, year = {2008}, month = {jul}, keywords = {2008, Multiple Fellows}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v78/i1/e013834}, author = {Francisco E Becerra and R T Willis and Steven L Rolston and Luis A Orozco} } @article {McCormick2008, title = {Strong low-frequency quantum correlations from a four-wave-mixing amplifier}, journal = {Phys. Rev. A}, volume = {78}, number = {4}, year = {2008}, month = {oct}, keywords = {2008, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v78/i4/e043816}, author = {C F McCormick and Alberto M Marino and Vincent Boyer and Paul D Lett} } @article { ISI:000262607800076, title = {Transport properties and Kondo correlations in nanostructures: Time-dependent DMRG method applied to quantum dots coupled to Wilson chains}, journal = {PHYSICAL REVIEW B}, volume = {78}, number = {19}, year = {2008}, month = {NOV}, issn = {1098-0121}, doi = {10.1103/PhysRevB.78.195317}, author = {da Silva, Luis G. G. V. D. and Heidrich-Meisner, F. and Feiguin, A. E. and Buesser, C. A. and Martins, G. B. and Anda, E. V. and Dagotto, E.} } @article {Marino2008, title = {Violation of the Cauchy-Schwarz Inequality in the Macroscopic Regime}, journal = {Phys. Rev. Lett.}, volume = {100}, number = {23}, year = {2008}, month = {jun}, keywords = {2008, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v100/i23/e233601}, author = {Alberto M Marino and Vincent Boyer and Paul D Lett} } @article {PEREZGALVAN2007, title = {Comparison of hyperfine anomalies in the 5S1/25S1/2 and 6S1/26S1/2 levels of 85Rb and 87Rb}, journal = {Phys. Lett. B}, volume = {655}, number = {3-4}, year = {2007}, month = {nov}, pages = {114{\textendash}118}, abstract = {We observe a hyperfine anomaly in the measurement of the hyperfine splitting of the 6S1/2 excited level in rubidium. We perform two step spectroscopy using the 5S1/2{\textrightarrow}5P1/2{\textrightarrow}6S1/2 excitation sequence. We measure the splitting of the 6S1/2 level and obtain for the magnetic dipole constants of 85Rb and 87Rb and , respectively. The hyperfine anomaly difference of comes from the Bohr Weisskopf effect: a correction to the point interaction between the finite nuclear magnetization and the electrons, and agrees with that obtained in the 5S1/2 ground state.}, keywords = {2007, 21.60.-n, 32.10.fn, 32.30.-r, Single Fellow}, issn = {03702693}, url = {http://dx.doi.org/10.1016/j.physletb.2007.09.042}, author = {A P{\'e}rez Galv{\'a}n and Zhao, Y and Luis A Orozco and Gomez, E. and A Lange and F Baumer and G Sprouse} } @article {Anderlini2007, title = {Controlled exchange interaction between pairs of neutral atoms in an optical lattice}, journal = {Nature}, volume = {448}, number = {7152}, year = {2007}, month = {jul}, pages = {452{\textendash}6}, abstract = {Ultracold atoms trapped by light offer robust quantum coherence and controllability, providing an attractive system for quantum information processing and for the simulation of complex problems in condensed matter physics. Many quantum information processing schemes require the manipulation and deterministic entanglement of individual qubits; this would typically be accomplished using controlled, state-dependent, coherent interactions among qubits. Recent experiments have made progress towards this goal by demonstrating entanglement among an ensemble of atoms confined in an optical lattice. Until now, however, there has been no demonstration of a key operation: controlled entanglement between atoms in isolated pairs. Here we use an optical lattice of double-well potentials to isolate and manipulate arrays of paired (87)Rb atoms, inducing controlled entangling interactions within each pair. Our experiment realizes proposals to use controlled exchange coupling in a system of neutral atoms. Although 87Rb atoms have nearly state-independent interactions, when we force two atoms into the same physical location, the wavefunction exchange symmetry of these identical bosons leads to state-dependent dynamics. We observe repeated interchange of spin between atoms occupying different vibrational levels, with a coherence time of more than ten milliseconds. This observation demonstrates the essential component of a neutral atom quantum SWAP gate (which interchanges the state of two qubits). Its {\textquoteright}half-implementation{\textquoteright}, the root SWAP gate, is entangling, and together with single-qubit rotations it forms a set of universal gates for quantum computation.}, keywords = {2007, Multiple Fellows}, issn = {1476-4687}, url = {http://dx.doi.org/10.1038/nature06011}, author = {Anderlini, M. and Patricia J Lee and Benjamin L Brown and Jennifer Sebby-Strabley and William D Phillips and J V Porto} } @conference {Bryant2007, title = {Controlling the optical properties of quantum dots and nanocrystals using size, composition and strain}, booktitle = {Proceedings of the SPIE}, volume = {6481}, number = {1}, year = {2007}, month = {feb}, pages = {648102{\textendash}648102{\textendash}11}, publisher = {SPIE}, organization = {SPIE}, keywords = {2007, Single Fellow}, issn = {0277786X}, url = {http://link.aip.org/link/?PSISDG/6481/648102/1}, author = {Garnett W Bryant and J G D{\'\i}az and M Zieli{\'n}ski and W Jask{\'o}lski} } @article {Rogers2007, title = {Detector dead-time effects and paralyzability in high-speed quantum key distribution}, journal = {New J. Phys.}, volume = {9}, number = {9}, year = {2007}, month = {sep}, pages = {319{\textendash}319}, abstract = {Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate, security concerns associated with detector dead times can limit the production rate of sifted bits. We present a model of high-speed QKD in this limit that identifies an optimum transmission rate for a system with given link loss and detector response characteristics.}, keywords = {2007, Single Fellow}, issn = {1367-2630}, url = {http://stacks.iop.org/1367-2630/9/i=9/a=319}, author = {Rogers, Daniel J and Bienfang, Joshua C. and Nakassis, Anastase and Hai Xu and Charles W Clark} } @article {Brey2007, title = {Diluted Graphene Antiferromagnet}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {11}, year = {2007}, month = {sep}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i11/e116802}, author = {Brey, L. and Fertig, H. A. and S. Das Sarma} } @article {Rey2007, title = {Entanglement and the Mott transition in a rotating bosonic ring lattice}, journal = {Phys. Rev. A}, volume = {75}, number = {6}, year = {2007}, month = {jun}, keywords = {2007, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v75/i6/e063616}, author = {A M Rey and Burnett, Keith and Indubala Satija and Charles W Clark} } @article {Wu2007, title = {Flat Bands and Wigner Crystallization in the Honeycomb Optical Lattice}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {7}, year = {2007}, month = {aug}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i7/e070401}, author = {Wu, Congjun and Doron L. Bergman and Balents, Leon and S. Das Sarma} } @article {Gomez2007, title = {Light forces in ultracold photoassociation}, journal = {Phys. Rev. A}, volume = {75}, number = {1}, year = {2007}, month = {jan}, pages = {7}, abstract = {We study the time-resolved photoassociation of ultracold sodium in an optical dipole trap. The photoassociation laser excites pairs of atoms to molecular states of large total angular momentum at high intensities (above 20 kW/cm\$\^{}\{2\}\$). Such transitions are generally suppressed at ultracold temperatures by the centrifugal barriers for high partial waves. Time-resolved ionization measurements reveal that the atoms are accelerated by the dipole potential of the photoassociation beam. We change the collision energy by varying the potential depth, and observe a strong variation of the photoassociation rate. These results demonstrate the important role of light forces in cw photoassociation at high intensities.}, keywords = {2007, Multiple Fellows}, issn = {1050-2947}, url = {http://arxiv.org/abs/physics/0611175}, author = {Gomez, E. and Black, A. and L D Turner and Eite Tiesinga and Paul D Lett} } @article {Zhang2007c, title = {Magnetism and anomalous Hall effect in Co-(La,Sr)TiO3}, journal = {Phys. Rev. B}, volume = {76}, number = {8}, year = {2007}, month = {aug}, pages = {85323}, keywords = {2007, and superparamagnetism, Diamagnetism, Galvanomagnetic and other magnetotransport effects, Magnetic semiconductors, No Fellows, paramagnetism}, issn = {1098-0121}, url = {http://adsabs.harvard.edu/abs/2007PhRvB..76h5323Z}, author = {Zhang, S. and Yu, W. and Ogale, S. and Shinde, S. and Kundaliya, D. and Tse, Wang-Kong and Young, S. and Higgins, J. and Salamanca-Riba, L. and Herrera, M. and Fu, L. and Browning, N. and Greene, R. and Venkatesan, T.} } @article {Tan2007, title = {Measurement of Scattering Rate and Minimum Conductivity in Graphene}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {24}, year = {2007}, month = {dec}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i24/e246803}, author = {Tan, Y.-W. and Zhang, Y. and Bolotin, K. and Zhao, Y and Shaffique Adam and E H Hwang and S. Das Sarma and Stormer, H. L. and Kim, P.} } @article {Sebby-Strabley2007, title = {Preparing and Probing Atomic Number States with an Atom Interferometer}, journal = {Phys. Rev. Lett.}, volume = {98}, number = {20}, year = {2007}, month = {may}, keywords = {2007, Multiple Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v98/i20/e200405}, author = {Jennifer Sebby-Strabley and Benjamin L Brown and Anderlini, M. and Patricia J Lee and William D Phillips and J V Porto and Philip R Johnson} } @article {Black2007, title = {Spinor Dynamics in an Antiferromagnetic Spin-1 Condensate}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {7}, year = {2007}, month = {aug}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i7/e070403}, author = {Black, A. and Gomez, E. and L D Turner and Jung, S. and Paul D Lett} } @article {McCormick2007, title = {Strong relative intensity squeezing by four-wave mixing in rubidium vapor}, journal = {Optics Letters}, volume = {32}, number = {2}, year = {2007}, month = {jan}, pages = {178}, publisher = {OSA}, abstract = {We have measured -3.5 dB (-8.1 dB corrected for losses) relative intensity squeezing between probe and conjugate beams generated by stimulated, nondegenerate four-wave mixing in hot rubidium vapor. Unlike early observations of squeezing in atomic vapors based on saturation of a two-level system, our scheme uses a resonant nonlinearity based on ground-state coherences in a three-level system. Since this scheme produces narrowband, squeezed light near an atomic resonance, it is of interest for experiments involving cold atoms or atomic ensembles.}, keywords = {2007, four-wave mixing, Nonlinear optics, Single Fellow, Squeezed states}, issn = {0146-9592}, url = {http://ol.osa.org/abstract.cfm?URI=ol-32-2-178}, author = {C F McCormick and Vincent Boyer and Arimondo, E. and Paul D Lett} } @article {Lee2007a, title = {Sublattice Addressing and Spin-Dependent Motion of Atoms in a Double-Well Lattice}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {2}, year = {2007}, month = {jul}, keywords = {2007, Multiple Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i2/e020402}, author = {Patricia J Lee and Anderlini, M. and Benjamin L Brown and Jennifer Sebby-Strabley and William D Phillips and J V Porto} } @article {Diaz2007, title = {Theory of InP nanocrystals under pressure}, journal = {Phys. Rev. B}, volume = {75}, number = {24}, year = {2007}, month = {jun}, keywords = {2007, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v75/i24/e245433}, author = {J G D{\'\i}az and Garnett W Bryant and W Jask{\'o}lski and M Zieli{\'n}ski} } @article {Boyer2007, title = {Ultraslow Propagation of Matched Pulses by Four-Wave Mixing in an Atomic Vapor}, journal = {Phys. Rev. Lett.}, volume = {99}, number = {14}, year = {2007}, month = {oct}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v99/i14/e143601}, author = {Vincent Boyer and C F McCormick and Arimondo, E. and Paul D Lett} } @article {Galitski2006, title = {Boundary conditions for spin diffusion in disordered systems}, journal = {Phys. Rev. B}, volume = {74}, number = {11}, year = {2006}, pages = {6}, abstract = {We develop a general scheme of deriving boundary conditions for spin-charge coupled transport in disordered systems with spin-orbit interactions. To illustrate the application of the method, we explicitly derive boundary conditions for spin diffusion in the Rashba model. Due to the surface spin precession, the boundary conditions are non-trivial and contain terms, which couple different components of the spin density. We argue that boundary conditions and the corresponding electric-field-induced spin accumulation generally depend on the nature of the boundary and therefore the spin Hall effect in a spin-orbit coupled system can be viewed as a non-universal edge phenomenon.}, keywords = {2006, Multiple Fellows}, issn = {1098-0121}, url = {http://arxiv.org/abs/cond-mat/0601677}, author = {Victor M Galitski and Burkov, Anton and S. Das Sarma} } @article {Tang2006, title = {Experimental study of high speed polarization-coding quantum key distribution with sifted-key rates over Mbit/s}, journal = {Optics Express}, volume = {14}, number = {6}, year = {2006}, pages = {2062}, publisher = {OSA}, abstract = {We present a quantitative study of various limitations on quantum cryptographic systems operating with sifted-key rates over Mbit/s. The dead time of silicon APDs not only limits the sifted-key rate but also causes correlation between the neighboring key bits. In addition to the well-known count-rate dependent timing jitter in avalanche photo-diode (APD), the faint laser sources, the vertical cavity surface emission lasers (VCSELs) in our system, also induce a significant amount of data-dependent timing jitter. Both the dead time and the data-dependent timing jitter are major limiting factors in designing QKD systems with sifted-key rates beyond Mbit/s.}, keywords = {2006, Fiber optics communications, Multiple Fellows, Optical communications, Photon counting, Quantum detectors}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-14-6-2062}, author = {Tang, Xiao and Ma, Lijun and Mink, Alan and Nakassis, Anastase and Hai Xu and Hershman, Barry and Bienfang, Joshua C. and Su, David and Boisvert, Ronald F. and Charles W Clark and Carl J Williams} } @article {Brey2006, title = {Mean-field theory for double perovskites: Coupling between itinerant electron spins and localized spins}, journal = {Phys. Rev. B}, volume = {74}, number = {9}, year = {2006}, month = {sep}, pages = {94429}, keywords = {2006, Colossal magnetoresistance, General theory and models of magnetic ordering, Single Fellow}, issn = {1098-0121}, url = {http://adsabs.harvard.edu/abs/2006PhRvB..74i4429B}, author = {Brey, L. and Calder{\'o}n, M.J. and S. Das Sarma and Guinea, F.} } @article {Zelevinsky2006, title = {Narrow Line Photoassociation in an Optical Lattice}, journal = {Phys. Rev. Lett.}, volume = {96}, number = {20}, year = {2006}, month = {may}, keywords = {2006, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v96/i20/e203201}, author = {Zelevinsky, T. and Boyd, M. M. and Ludlow, A. D. and Ido, T. and Jun Ye and Roman Ciurylo and Pascal Naidon and Paul S Julienne} } @article {Romero2006, title = {Plasmons in nearly touching metallic nanoparticles: singular response in the limit of touching dimers}, journal = {Optics Express}, volume = {14}, number = {21}, year = {2006}, month = {oct}, pages = {9988}, publisher = {OSA}, abstract = {The response of gold nanoparticle dimers is studied theoretically near and beyond the limit where the particles are touching. As the particles approach each other, a dominant dipole feature is observed that is pushed into the infrared due to interparticle coupling and that is associated with a large pileup of induced charge in the interparticle gap. The redshift becomes singular as the particle separation decreases. The response weakens for very small separation when the coupling across the interparticle gap becomes so strong that dipolar oscillations across the pair are inhibited. Lowerwavelength, higher-order modes show a similar separation dependence in nearly touching dimers. After touching, singular behavior is observed through the emergence of a new infrared absorption peak, also accompanied by huge charge pileup at the interparticle junction, if initial interparticle-contact is made at a single point. This new mode is distinctly different from the lowest mode of the separated dimer. When the junction is made by contact between flat surfaces, charge at the junction is neutralized and mode evolution is continuous through contact. The calculated singular response explains recent experiments on metallic nanoparticle dimers and is relevant in the design of nanoparticle-based sensors and plasmon circuits.}, keywords = {2006, Particles, Single Fellow, Surface plasmons}, issn = {1094-4087}, url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-14-21-9988}, author = {Romero, Isabel and Javier Aizpurua and Garnett W Bryant and Javier F Garc{\'\i}a De Abajo} } @article {Diaz2006a, title = {Pressure-induced optoelectronic properties of InP nanocrystals: Tight-binding approach}, journal = {Phys. Status Solidi C}, volume = {3}, number = {11}, year = {2006}, month = {dec}, pages = {3823{\textendash}3826}, keywords = {2006, Single Fellow}, issn = {16101634}, doi = {10.1002/pssc.200671553}, url = {http://adsabs.harvard.edu/abs/2006PSSCR...3.3823D}, author = {J G D{\'\i}az and Garnett W Bryant and W Jask{\'o}lski and M Zieli{\'n}ski} } @article {Zhang2006a, title = {Semiconductor-Metal Nanoparticle Molecules: Hybrid Excitons and the Nonlinear Fano Effect}, journal = {Phys. Rev. Lett.}, volume = {97}, number = {14}, year = {2006}, month = {oct}, keywords = {2006, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v97/i14/e146804}, author = {Zhang, Wei and Govorov, Alexander and Garnett W Bryant} } @article {Jaskolski2006, title = {Strain effects on the electronic structure of strongly coupled self-assembled InAs/GaAs quantum dots: Tight-binding approach}, journal = {Phys. Rev. B}, volume = {74}, number = {19}, year = {2006}, month = {nov}, pages = {1{\textendash}11}, keywords = {2006, Single Fellow}, issn = {1098-0121}, url = {http://www.mendeley.com/research/electronic-structure-selfassembled-inasinp-quantum-dots-comparison-selfassembled-inasgaas-quantum-dots/}, author = {W Jask{\'o}lski and M Zieli{\'n}ski and Garnett W Bryant and Javier Aizpurua} } @article {Banerjee2006, title = {A study of the personal income distribution in Australia}, journal = {Physica A: Statistical Mechanics and its Applications}, volume = {370}, number = {1}, year = {2006}, month = {oct}, pages = {54{\textendash}59}, abstract = {We analyze the data on personal income distribution from the Australian Bureau of Statistics. We compare fits of the data to the exponential, log-normal, and gamma distributions. The exponential function gives a good (albeit not perfect) description of 98\% of the population in the lower part of the distribution. The log-normal and gamma functions do not improve the fit significantly, despite having more parameters, and mimic the exponential function. We find that the probability density at zero income is not zero, which contradicts the log-normal and gamma distributions, but is consistent with the exponential one. The high-resolution histogram of the probability density shows a very sharp and narrow peak at low incomes, which we interpret as the result of a government policy on income redistribution.}, keywords = {2006, australia, econophysics, income distribution, Single Fellow}, issn = {03784371}, url = {http://dx.doi.org/10.1016/j.physa.2006.04.023}, author = {Banerjee, Anand and Victor M Yakovenko and T Di Matteo} } @article {Belyanin2006, title = {Superfluorescence from dense electron-hole plasmas in high magnetic fields}, journal = {J. Phys.: Conf. Ser.}, volume = {51}, number = {1}, year = {2006}, month = {nov}, pages = {403{\textendash}406}, abstract = {Cooperative spontaneous recombination (superfluorescence) of electron-hole plasmas in semiconductors has been a challenge to observe due to ultrafast decoherence. We argue that superfluorescence can be achieved in quantum-confined semiconductor systems and present experimental evidence for superfluorescence from high-density photoexcited electronhole plasmas in magnetized quantum wells. At a critical magnetic field strength and excitation fluence, we observe a clear transition in the band-edge photoluminescence from omnidirectional output to a randomly directed but highly collimated beam. Changes in the linewidth, carrier density, and magnetic field scaling of the emission spectra correlate precisely with the onset of random directionality and are consistent with cooperative recombination.}, keywords = {2006, Single Fellow}, issn = {1742-6588}, url = {http://stacks.iop.org/1742-6596/51/i=1/a=093}, author = {A A Belyanin and Jho, Y. D. and Wang, X. and Kono, J. and Reitze, D. H. and Wei, X and Glenn S Solomon} } @article {Diaz2006, title = {Tight-binding theory of ZnS/CdS nanoscale heterostructures: Role of strain and d orbitals}, journal = {Phys. Rev. B}, volume = {74}, number = {20}, year = {2006}, month = {nov}, keywords = {2006, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v74/i20/e205309}, author = {J G D{\'\i}az and M Zieli{\'n}ski and W Jask{\'o}lski and Garnett W Bryant} } @article {Joglekar2006, title = {Wigner supersolid of excitons in electron-hole bilayers}, journal = {Phys. Rev. B}, volume = {74}, number = {23}, year = {2006}, month = {dec}, keywords = {2006, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v74/i23/e233302}, author = {Joglekar, Yogesh and Balatsky, Alexander and S. Das Sarma} }