Optical lever detection is a simple and robust method to measure small displacements. We report on our experimental efforts toward reaching and surpassing the quantum backaction limits of this method when probing a high Q nanomechanical resonator. (C) 2020 The Author(s)

}, isbn = {978-1-943580-76-7}, author = {Hao, Shan and Singh, Robinjeet and Purdy, Thomas P.} } @article { ISI:000510146100001, title = {Quantum many-body scar states with emergent kinetic constraints and finite-entanglement revivals}, journal = {Phys. Rev. B}, volume = {101}, number = {2}, year = {2020}, month = {JAN 29}, pages = {024306}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We construct a set of exact, highly excited eigenstates for a nonintegrable spin-1/2 model in one dimension that is relevant to experiments on Rydberg atoms in the antiblockade regime. These states provide a new solvable example of quantum many-body scars: their sub-volume-law entanglement and equal energy spacing allow for infinitely long-lived coherent oscillations of local observables following a suitable quantum quench. While previous works on scars have interpreted such oscillations in terms of the precession of an emergent macroscopic SU(2) spin, the present model evades this description due to a set of emergent kinetic constraints in the scarred eigenstates that are absent in the underlying Hamiltonian. We also analyze the set of initial states that give rise to periodic revivals, which persist as approximate revivals on a finite timescale when the underlying model is perturbed. Remarkably, a subset of these initial states coincides with the family of area-law entangled Rokhsar-Kivelson states shown by Lesanovsky to be exact ground states for a class of models relevant to experiments on Rydberg-blockaded atomic lattices.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.101.024306}, author = {Iadecola, Thomas and Schecter, Michael} } @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 {anastopoulos_quantum_2020, title = {Quantum superposition of two gravitational cat states}, journal = {Class. Quantum Gravity}, volume = {37}, number = {23}, year = {2020}, note = {Place: TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND Publisher: IOP PUBLISHING LTD Type: Article}, month = {dec}, abstract = {We extend our earlier work [1] on probing a gravitational cat state (gravcat) to the quantum superposition of two gravcats in an exemplary model and in Bose-Einstein condensates (BEC). In addition to its basic theoretical values in gravitational quantum physics and macroscopic quantum phenomena, this investigation can provide some theoretical support to experimental proposals for measuring gravity-induced entanglement and the quantum nature of perturbative gravity. In the first part we consider cat states generated by double-well potentials. A pair of gravcats, each approximated as a two-level system, is characterized by gravity-induced Rabi oscillations, and by gravity-induced entanglement of its energy eigenstates. In the second part we turn to a (non-relativistic) quantum field theory description and derive a gravitational Gross-Pitaevsky equation for gravcats formed in BEC. Using a mathematical analogy to quantum rotors, we explore the properties of the two-gravcat system for BECs, its physical consequences and observational possibilities. Finally we discuss our results in comparison to predictions of alternative quantum theories, and we explain their implications.}, keywords = {Bose Einstein condensates, entanglement, gravitational decoherence, gravitational quantum physics, quantum superpositions}, issn = {0264-9381}, doi = {10.1088/1361-6382/abbe6f}, author = {Anastopoulos, C. and Hu, B. L.} } @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 {ISI:000484374000020, title = {Quantum electrodynamics of a superconductor-insulator phase transition}, journal = {Nat. Phys.}, volume = {15}, number = {9}, year = {2019}, month = {SEP}, pages = {930+}, publisher = {NATURE PUBLISHING GROUP}, type = {Article}, abstract = {A chain of Josephson junctions represents one of the simplest many-body models undergoing a superconductor-insulator quantum phase transition(1,2). Apart from zero resistance, the superconducting state is necessarily accompanied by a sound-like mode due to collective oscillations of the phase of the complex-valued order parameter(3,4). Little is known about the fate of this mode on entering the insulating state, where the order parameter{\textquoteright}s amplitude remains non-zero, but the phase ordering is {\textquoteleft}melted{\textquoteright} by quantum fluctuations(5). Here, we show that the phase mode survives far into the insulating regime, such that megaohm-resistance chains can carry gigahertz-frequency alternating currents as nearly ideal superconductors. The insulator reveals itself through interaction-induced broadening and random frequency shifts of collective mode resonances. Our spectroscopic experiment puts forward the problem of quantum electrodynamics of a Bose glass for both theory and experiments(6-8). By pushing the chain parameters deeper into the insulating state, we achieved a wave impedance of the phase mode exceeding the predicted critical value by an order of magnitude(9-14). The effective fine structure constant of such a one-dimensional electromagnetic vacuum exceeds unity, promising transformative applications to quantum science and technology.}, issn = {1745-2473}, doi = {10.1038/s41567-019-0553-1}, author = {Kuzmin, R. and Mencia, R. and Grabon, N. and Mehta, N. and Lin, Y-H and Manucharyan, V. E.} } @article {ISI:000468373300008, title = {Quantum frequency conversion of a quantum dot single-photon source on a nanophotonic chip}, journal = {Optica}, volume = {6}, number = {5}, year = {2019}, month = {MAY 20}, pages = {563-569}, publisher = {OPTICAL SOC AMER}, type = {Article}, abstract = {Single self-assembled InAs/GaAs quantum dots are promising bright sources of indistinguishable photons for quantum information science. However, their distribution in emission wavelength, due to inhomogeneous broadening inherent to their growth, has limited the ability to create multiple identical sources. Quantum frequency conversion can overcome this issue, particularly if implemented using scalable chip-integrated technologies. Here, we report the first demonstration to our knowledge of quantum frequency conversion of a quantum dot single-photon source on a silicon nanophotonic chip. Single photons from a quantum dot in a micropillar cavity are shifted in wavelength with an on-chip conversion efficiency approximate to 12\%, limited by the linewidth of the quantum dot photons. The intensity auto-correlation function g((2)) (tau) for the frequency-converted light is antibunched with g((2)) (0) = 0.290 +/- 0.030, compared to the before-conversion value g((2)) (0) = 0.080 +/- 0.003. We demonstrate the suitability of our frequency-conversion interface as a resource for quantum dot sources by characterizing its effectiveness across a wide span of input wavelengths (840-980 nm) and its ability to achieve tunable wavelength shifts difficult to obtain by other approaches. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement}, issn = {2334-2536}, doi = {10.1364/OPTICA.6.000563}, author = {Singh, Anshuman and Li, Qing and Liu, Shunfa and Yu, Ying and Lu, Xiyuan and Schneider, Christian and Hoefling, Sven and Lawall, John and Verma, Varun and Mirin, Richard and Nam, Sae Woo and Liu, Jin and Srinivasan, Kartik} } @article {ISI:000485187000003, title = {Quantum information scrambling through a high-complexity operator mapping}, journal = {Phys. Rev. A}, volume = {100}, number = {3}, year = {2019}, month = {SEP 6}, pages = {032309}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Quantum information scrambling has attracted much attention amid the effort to reconcile the conflict between quantum-mechanical unitarity and the thermalization irreversibility in many-body systems. Here we propose an unconventional mechanism to generate quantum information scrambling through a high-complexity mapping from logical to physical degrees-of-freedom that hides the logical information into nonseparable many-body correlations. Corresponding to this mapping, we develop an algorithm to efficiently sample a Slater-determinant wave function and compute all physical observables in dynamics with a polynomial cost in system size. The system shows information scrambling in the quantum many-body Hilbert space characterized by the spreading of Hamming distance. At late time we find emergence of classical diffusion dynamics in this quantum many-body system. We establish that the operator mapping enabled growth in an out-of-time-order correlator exhibits exponential-scrambling behavior. The quantum information-hiding mapping approach may shed light on the understanding of fundamental connections among computational complexity, information scrambling, and quantum thermalization.}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.032309}, author = {Li, Xiaopeng and Zhu, Guanyu and Han, Muxin and Wang, Xin} } @article {ISI:000466809600017, title = {QUANTUM INFORMATION The US National Quantum Initiative: From Act to action}, journal = {Science}, volume = {364}, number = {6439}, year = {2019}, month = {MAY 3}, pages = {440-442}, publisher = {AMER ASSOC ADVANCEMENT SCIENCE}, type = {Editorial Material}, issn = {0036-8075}, doi = {10.1126/science.aax0578}, author = {Monroe, Christopher and Raymer, Michael G. and Taylor, Jacob} } @article { ISI:000496930000002, title = {Quantum Interference between Photons from an Atomic Ensemble and a Remote Atomic Ion}, journal = {Phys. Rev. Lett.}, volume = {123}, number = {21}, year = {2019}, month = {NOV 18}, pages = {213601}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Many remote-entanglement protocols rely on the generation and interference of photons produced by nodes within a quantum network. Quantum networks based on heterogeneous nodes provide a versatile platform by utilizing the complementary strengths of the differing systems. Implementation of such networks is challenging, due to the disparate spectral and temporal characteristics of the photons generated by the different quantum systems. Here, we report on the observation of quantum interference between photons generated from a single ion and an atomic ensemble. The photons are produced on demand by each source located in separate buildings, in a manner suitable for quantum networking. Given these results, we analyze the feasibility of hybrid ion-ensemble remote entanglement generation.}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.123.213601}, author = {Craddock, A. N. and Hannegan, J. and Ornelas-Huerta, D. P. and Siverns, J. D. and Hachtel, A. J. and Goldschmidt, A. and Porto, J. V. and Quraishi, Q. and Rolston, S. L.} } @article { ISI:000498849400002, title = {Quantum many-body scars from magnon condensation}, journal = {Phys. Rev. B}, volume = {100}, number = {18}, year = {2019}, month = {NOV 27}, pages = {184312}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {We study the eigenstate properties of a nonintegrable spin chain that was recently realized experimentally in a Rydberg-atom quantum simulator. In the experiment, long-lived coherent many-body oscillations were observed only when the system was initialized in a particular product state. This pronounced coherence has been attributed to the presence of special {\textquoteleft}{\textquoteleft}scarred{{\textquoteright}{\textquoteright}} eigenstates with nearly equally spaced energies and putative nonergodic properties despite their finite energy density. In this paper we uncover a surprising connection between these scarred eigenstates and low-lying quasiparticle excitations of the spin chain. In particular, we show that these eigenstates can be accurately captured by a set of variational states containing a macroscopic number of magnons with momentum pi. This leads to an interpretation of the scarred eigenstates as finite-energy-density condensates of weakly interacting pi magnons. One natural consequence of this interpretation is that the scarred eigenstates possess long-range connected correlations in both space and time. We verify numerically the presence of this spatiotemporal long-range order and explain how it is consistent with established no-go theorems precluding its existence in ground states and at thermal equilibrium.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.184312}, author = {Iadecola, Thomas and Schecter, Michael and Xu, Shenglong} } @article {ISI:000476860700002, title = {Quantum repeaters based on two species trapped ions}, journal = {New J. Phys.}, volume = {21}, year = {2019}, month = {JUL 1}, pages = {073002}, publisher = {IOP PUBLISHING LTD}, type = {Article}, abstract = {We examine the viability of quantum repeaters based on two-species trapped ion modules for long-distance quantum key distribution. Repeater nodes comprised of ion-trap modules of co-trapped ions of distinct species are considered. The species used for communication qubits has excellent optical properties while the other longer lived species serves as a memory qubit in the modules. Each module interacts with the network only via single photons emitted by the communication ions. Coherent Coulomb interaction between ions is utilized to transfer quantum information between the communication and memory ions and to achieve entanglement swapping between two memory ions. We describe simple modular quantum repeater architectures realizable with the ion-trap modules and numerically study the dependence of the quantum key distribution rate on various experimental parameters, including coupling efficiency, gate infidelity, operation time and length of the elementary links. Our analysis suggests crucial improvements necessary in a physical implementation for co-trapped two-species ions to be a competitive platform in long-distance quantum communication.}, keywords = {quantum key distribution, quantum repeaters, two species trapped ions}, issn = {1367-2630}, doi = {10.1088/1367-2630/ab2a45}, author = {Santra, Siddhartha and Muralidharan, Sreraman and Lichtman, Martin and Jiang, Liang and Monroe, Christopher and Malinovsky, Vladimir S.} } @article {ISI:000472681100001, title = {Quantum Sensing with Squeezed Light}, journal = {ACS Photonics}, volume = {6}, number = {6}, year = {2019}, month = {JUN}, pages = {1307-1318}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {The minimum resolvable signal in sensing and metrology platforms that rely on optical readout fields is increasingly constrained by the standard quantum limit, which is determined by the sum of photon shot noise and back-action noise. A combination of back-action and shot noise reduction techniques will be critical to the development of the next generation of sensors for applications ranging from high-energy physics to biochemistry and for novel microscopy platforms capable of resolving material properties that were previously obscured by quantum noise. This Perspective reviews the dramatic advances made in the use of squeezed light for sub-shot-noise quantum sensing in recent years and highlights emerging applications that enable new science based on signals that would otherwise be obscured by noise at the standard quantum limit.}, keywords = {continuous variable quantum optics, quantum noise reduction, quantum sensing, squeezing}, issn = {2330-4022}, doi = {10.1021/acsphotonics.9b00250}, author = {Lawrie, B. J. and Lett, P. D. and Marino, A. M. and Pooser, R. C.} } @article {ISI:000482580900004, title = {Quantum work of an optical lattice}, journal = {Phys. Rev. B}, volume = {100}, number = {6}, year = {2019}, month = {AUG 26}, pages = {064308}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {A classic example of a quantum quench concerns the release of an interacting Bose gas from an optical lattice. The local properties of quenches such as this have been extensively studied; however, the global properties of these nonequilibrium quantum systems have received far less attention. Here we study several aspects of global nonequilibrium behavior by calculating the amount of work done by the quench as measured through the work distribution function. Using Bethe ansatz techniques, we determine the Loschmidt amplitude and work distribution function of the Lieb-Liniger gas after it is released from an optical lattice. We find the average work and its universal edge exponents from which we determine the long-time decay of the Loschmidt echo and highlight striking differences caused by the interactions as well as changes in the geometry of the system. We extend our calculation to the attractive regime of the model and show that the system exhibits properties similar to the super-Tonks-Girardeau gas. Finally, we examine the prominent role played by bound states in the work distribution and show that, with low probability, they allow for work to be extracted from the quench.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.100.064308}, author = {Rylands, Colin and Andrei, Natan} } @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:000447638200072, title = {QFlow lite dataset: A machine-learning approach to the charge states in quantum dot experiments}, journal = {PLOS ONE}, volume = {13}, number = {10}, year = {2018}, month = {OCT 17}, pages = {e0205844}, issn = {1932-6203}, doi = {10.1371/journal.pone.0205844}, author = {Zwolak, Justyna P. and Kalantre, Sandesh S. and Wu, Xingyao and Ragole, Stephen and Taylor, Jacob M.} } @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:000449780400004, title = {Quantum field theory for the chiral clock transition in one spatial dimension}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {20}, year = {2018}, month = {NOV 9}, pages = {205118}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.205118}, author = {Whitsitt, Seth and Samajdar, Rhine and Sachdev, Subir} } @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:000447918000003, title = {Quantum inverse freezing and mirror-glass order}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {14}, year = {2018}, month = {OCT 22}, pages = {144204}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.144204}, author = {Iadecola, Thomas and Schecter, Michael} } @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:000436275400032, title = {Quantum Thermodynamics at Strong Coupling: Operator Thermodynamic Functions and Relations}, journal = {ENTROPY}, volume = {20}, number = {6}, year = {2018}, month = {JUN}, pages = {423}, keywords = {operator thermodynamic functions, quantum thermodynamics, strong coupling}, issn = {1099-4300}, doi = {10.3390/e20060423}, author = {Hsiang, Jen-Tsung and Hu, Bei-Lok} } @article { ISI:000423237900002, title = {Quantum thermodynamics from the nonequilibrium dynamics of open systems: Energy, heat capacity, and the third law}, journal = {PHYSICAL REVIEW E}, volume = {97}, number = {1}, year = {2018}, month = {JAN 23}, pages = {012135}, issn = {2470-0045}, doi = {10.1103/PhysRevE.97.012135}, author = {Hsiang, J. -T. and Chou, C. H. and Subasi, Y. and Hu, B. L.} } @article { ISI:000438348200004, title = {Quantum transport in graphene p-n junctions with moire superlattice modulation}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {4}, year = {2018}, month = {JUL 12}, pages = {045412}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.045412}, author = {Hu, Jiuning and Rigosi, Albert F. and Lee, Ji U. and Lee, Hsin-Yen and Yang, Yanfei and Liu, I, Chieh- and Elmquist, Randolph E. and Newell, David B.} } @article { ISI:000454161400003, title = {Quasiparticle gaps in multiprobe Majorana nanowires}, journal = {PHYSICAL REVIEW B}, volume = {98}, number = {22}, year = {2018}, month = {DEC 18}, pages = {224512}, abstract = {We theoretically study a spin-orbit-coupled nanowire proximitized by a superconductor in the presence of an externally applied Zeeman field ({{\textquoteright}{\textquoteright}}Majorana nanowire{{\textquoteright}{\textquoteright}}) with zero-energy Majorana bound states localized at the two ends of the wire when the Zeeman spin splitting is large enough for the system to enter the topological phase. The specific physics of interest in the current work is the effect of having several tunnel probes attached to the wire along its length. Such tunnel probes should allow, as a matter of principle, one to observe both the predicted bulk superconducting gap closing and opening associated with the topological quantum phase transition as well as the Majorana bound states at the wire ends showing up as zero-bias conductance peaks, depending on which probes are used for the tunneling spectroscopy measurement. Because of the possible invasive nature of the tunnel probes, producing local potential fluctuations in the nanowire, we find the physical situation to be quite complex. In particular, depending on the details of the tunnel barrier operational at the probes, the Majorana nanowire could manifest additional low-energy Andreev bound states which will manifest their own almost-zero-bias peaks, complicating the interpretation of the tunneling data in multiprobe Majorana nanowires. We use two complementary microscopic models to simulate the probes, finding that the tunneling conductance spectrum depends rather sensitively on the details of the tunnel barriers at the probes, but in some situations it should be possible to observe the Majorana bound-state-induced zero-bias conductance peak at the wire ends along with the gap closing and opening features associated with the bulk topological quantum phase transition in the multiprobe Majorana nanowires. Our detailed numerical results indicate that such a system should also be capable of directly manifesting the nonlocal conductance correlations arising from Majorana bound states at the two ends of the nanowire. We apply our general analysis to simulate a recent multiprobe nanowire experiment commenting on the nature of the quasiparticle gaps likely controlling the experimental observations.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.98.224512}, author = {Huang, Yingyi and Sau, Jay D. and Stanescu, Tudor D. and S. Das Sarma} } @article { ISI:000443584000010, title = {Quo vadis now, cold molecules?}, journal = {NATURE PHYSICS}, volume = {14}, number = {9}, year = {2018}, month = {SEP}, pages = {873-874}, issn = {1745-2473}, doi = {10.1038/s41567-018-0260-3}, author = {Julienne, Paul S.} } @article {7271, title = {Quantum correlations from a room-temperature optomechanical cavity}, journal = {Science}, volume = {356}, year = {2017}, pages = {1265{\textendash}1268}, abstract = {Quantum back action{\textemdash}the {\textquotedblleft}reaction{\textquotedblright} of a quantum mechanical object to being measured{\textemdash}is normally observed at cryogenic temperatures, where it is easier to distinguish from thermal motion. Purdy et al. managed to tease out the effects of quantum back action at room temperature by using a mechanical oscillator and probing it with light (see the Perspective by Harris). The fluctuations of the force produced by the light probe caused correlated changes to the motion of the oscillator and the properties of the transmitted light. These correlations revealed the effects of the back action, which allows the system to be used as a quantum thermometer.Science, this issue p. 1265; see also p. 1232The act of position measurement alters the motion of an object being measured. This quantum measurement backaction is typically much smaller than the thermal motion of a room-temperature object and thus difficult to observe. By shining laser light through a nanomechanical beam, we measure the beam{\textquoteright}s thermally driven vibrations and perturb its motion with optical force fluctuations at a level dictated by the Heisenberg measurement-disturbance uncertainty relation. We demonstrate a cross-correlation technique to distinguish optically driven motion from thermally driven motion, observing this quantum backaction signature up to room temperature. We use the scale of the quantum correlations, which is determined by fundamental constants, to gauge the size of thermal motion, demonstrating a path toward absolute thermometry with quantum mechanically calibrated ticks.

}, issn = {0036-8075}, doi = {10.1126/science.aag1407}, url = {http://science.sciencemag.org/content/356/6344/1265}, author = {Purdy, T. P. and Grutter, K. E. and Srinivasan, K. and Taylor, J. M.} } @article {ISI:000401235900001, title = {Quantum Entanglement in Neural Network States}, journal = {PHYSICAL REVIEW X}, volume = {7}, number = {2}, year = {2017}, month = {MAY 11}, abstract = {Machine learning, one of today{\textquoteright}s most rapidly growing interdisciplinary fields, promises an unprecedented perspective for solving intricate quantum many-body problems. Understanding the physical aspects of the representative artificial neural-network states has recently become highly desirable in the applications of machine-learning techniques to quantum many-body physics. In this paper, we explore the data structures that encode the physical features in the network states by studying the quantum entanglement properties, with a focus on the restricted-Boltzmann-machine (RBM) architecture. We prove that the entanglement entropy of all short-range RBM states satisfies an area law for arbitrary dimensions and bipartition geometry. For long-range RBM states, we show by using an exact construction that such states could exhibit volume-law entanglement, implying a notable capability of RBM in representing quantum states with massive entanglement. Strikingly, the neural-network representation for these states is remarkably efficient, in the sense that the number of nonzero parameters scales only linearly with the system size. We further examine the entanglement properties of generic RBM states by randomly sampling the weight parameters of the RBM. We find that their averaged entanglement entropy obeys volume-law scaling, and the meantime strongly deviates from the Page entropy of the completely random pure states. We show that their entanglement spectrum has no universal part associated with random matrix theory and bears a Poisson-type level statistics. Using reinforcement learning, we demonstrate that RBM is capable of finding the ground state (with power-law entanglement) of a model Hamiltonian with a long-range interaction. In addition, we show, through a concrete example of the one-dimensional symmetry-protected topological cluster states, that the RBM representation may also be used as a tool to analytically compute the entanglement spectrum. Our results uncover the unparalleled power of artificial neural networks in representing quantum many-body states regardless of how much entanglement they possess, which paves a novel way to bridge computer-science-based machine-learning techniques to outstanding quantum condensed-matter physics problems.}, issn = {2160-3308}, doi = {10.1103/PhysRevX.7.021021}, author = {Deng, Dong-Ling and Li, Xiaopeng and S. Das Sarma} } @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:000418652100002, title = {Quantum phases of two-component bosons with spin-orbit coupling in optical lattices}, journal = {PHYSICAL REVIEW A}, volume = {96}, number = {6}, year = {2017}, month = {DEC 26}, pages = {061603}, publisher = {AMER PHYSICAL SOC}, type = {Article}, abstract = {Ultracold bosons in optical lattices are one of the few systems where bosonic matter is known to exhibit strong correlations. Here we push the frontier of our understanding of interacting bosons in optical lattices by adding synthetic spin-orbit coupling, and show that new kinds of density and chiral orders develop. The competition between the optical lattice period and the spin-orbit coupling length-which can be made comparable in experiments-along with the spin hybridization induced by a transverse field (i.e., Rabi coupling) and interparticle interactions create a rich variety of quantum phases including uniform, nonuniform, and phase-separated superfluids, as well as Mott insulators. The spontaneous symmetry-breaking phenomena at the transitions between them are explained by a two-order-parameter Ginzburg-Landau model with multiparticle umklapp processes. Finally, in order to characterize each phase, we calculated their experimentally measurable crystal momentum distributions.}, \%\%Address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, issn = {2469-9926}, doi = {10.1103/PhysRevA.96.061603}, author = {Yamamoto, Daisuke and Ian B Spielman and de Melo, C. A. R. Sa} } @article {ISI:000418786600007, title = {Quantum Redirection of Antenna Absorption to Photosynthetic Reaction Centers}, journal = {JOURNAL OF PHYSICAL CHEMISTRY LETTERS}, volume = {8}, number = {24}, year = {2017}, month = {DEC 21}, pages = {6015-6021}, publisher = {AMER CHEMICAL SOC}, type = {Article}, abstract = {The early steps of photosynthesis involve the photoexcitation of reaction centers (RCs) and light-harvesting (LH) units. Here, we show that the historically overlooked excitonic delocalization across RC and LH pigments results in a redistribution of absorption amplitudes that benefits the absorption cross section of the optical bands associated with the RC of several species. While we prove that this redistribution is robust to the microscopic details of the dephasing between these units in the purple bacterium Rhodospirillum rubrum, we are able to show that the redistribution witnesses a more fragile, but persistent, coherent population dynamics which directs excitations from the LH toward the RC units under incoherent illumination and physiological conditions. Even though the redirection does not seem to affect importantly the overall efficiency in photosynthesis, stochastic optimization allows us to delineate clear guidelines and develop simple analytic expressions in order to amplify the coherent redirection in artificial nanostructures.}, \%\%Address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.7b02714}, author = {Caycedo-Soler, Felipe and Schroeder, Christopher A. and Autenrieth, Caroline and Pick, Arne and Ghosh, Robin and Huelga, Susana F. and Plenio, Martin B.} } @article {7376, title = {Quantum simulation of a Fermi{\textendash}Hubbard model using a semiconductor quantum dot array}, journal = {Nature}, volume = {548}, year = {2017}, month = {08/2017}, pages = {70{\textendash}73}, isbn = {0028-0836}, url = {http://dx.doi.org/10.1038/nature23022}, author = {Hensgens, T and Fujita, T and Janssen, L and Li, Xiao and Van Diepen, C J. and Reichl, C and Wegscheider, W and S. Das Sarma and Vandersypen, L M. K.} } @article {ISI:000374726000029, title = {QUANTUM CONNECTIONS}, journal = {SCIENTIFIC AMERICAN}, volume = {314}, number = {5}, year = {2016}, month = {MAY}, pages = {50-57}, issn = {0036-8733}, author = {Monroe, Christopher R. and Schoelkopf, Robert J. and Lukin, Mikhail D.} } @article {ISI:000376992800002, title = {Quantum model for entropic springs}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {21}, year = {2016}, month = {JUN 2}, pages = {214102}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.214102}, author = {Wang, Chiao-Hsuan and Taylor, Jacob M.} } @article { ISI:000376908700003, title = {Quantum nonergodicity and fermion localization in a system with a single-particle mobility edge}, journal = {PHYSICAL REVIEW B}, volume = {93}, number = {18}, year = {2016}, month = {MAY 31}, pages = {184204}, issn = {2469-9950}, doi = {10.1103/PhysRevB.93.184204}, author = {Li, Xiaopeng and Pixley, J. H. and Deng, Dong-Ling and Ganeshan, Sriram and S. Das Sarma} } @article { ISI:000370215200053, title = {Quantum Phase Slips in 6 mm Long Niobium Nanowire}, journal = {NANO LETTERS}, volume = {16}, number = {2}, year = {2016}, month = {FEB}, pages = {1173-1178}, issn = {1530-6984}, doi = {10.1021/acs.nanolett.5b04473}, author = {Zhao, Weiwei and Liu, Xin and Chan, M. H. W.} } @article {4154, title = {A quantum phase switch between a single solid-state spin and a photon}, journal = {Nature Nanotechnology}, volume = {11}, year = {2016}, month = {02/2016}, pages = {539}, doi = {10.1038/nnano.2015.334}, url = {http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2015.334.html}, author = {Sun, Shuo and Kim, Hyochul and Solomon, Glenn S. and Waks, Edo} } @article { ISI:000383144000007, title = {Quantum phases of interacting electrons in three-dimensional dirty Dirac semimetals}, journal = {PHYSICAL REVIEW B}, volume = {94}, number = {11}, year = {2016}, month = {SEP 14}, pages = {115137}, issn = {2469-9950}, doi = {10.1103/PhysRevB.94.115137}, author = {Roy, Bitan and S. Das Sarma} } @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:000355254200016, title = {A quantitative study of bias triangles presented in chemical potential space}, journal = {JOURNAL OF PHYSICS-CONDENSED MATTER}, volume = {27}, number = {23}, year = {2015}, month = {JUN 17}, issn = {0953-8984}, doi = {10.1088/0953-8984/27/23/235302}, author = {Perron, Justin K. and Stewart, Jr., M. D. and Zimmerman, Neil M.} } @article { ISI:000368079400004, title = {Quantum entanglement at high temperatures? Bosonic systems in nonequilibrium steady state}, journal = {JOURNAL OF HIGH ENERGY PHYSICS}, number = {11}, year = {2015}, month = {NOV 13}, issn = {1029-8479}, doi = {10.1007/JHEP11(2015)090}, author = {Hsiang, Jen-Tsung and Hu, B. L.} } @article { ISI:000357020000003, title = {Quantum interference phenomena in the Casimir effect}, journal = {PHYSICAL REVIEW A}, volume = {91}, number = {6}, year = {2015}, month = {JUN 29}, pages = {062512}, issn = {1050-2947}, doi = {10.1103/PhysRevA.91.062512}, author = {Allocca, Andrew A. and Wilson, Justin H. and Victor M Galitski} } @article {ISI:000353646800011, title = {Quantum many-body models with cold atoms coupled to photonic crystals}, journal = {NATURE PHOTONICS}, volume = {9}, number = {5}, year = {2015}, month = {MAY}, pages = {326-331}, issn = {1749-4885}, doi = {10.1038/NPHOTON.2015.57}, author = {Douglas, J. S. and Habibian, H. and Hung, C. -L. and Gorshkov, A. V. and Kimble, H. J. and Chang, D. E.} } @article { ISI:000348392400007, title = {Quantum nonlinear optics near optomechanical instabilities}, journal = {PHYSICAL REVIEW A}, volume = {91}, number = {1}, year = {2015}, month = {JAN 9}, pages = {013818}, issn = {1050-2947}, doi = {10.1103/PhysRevA.91.013818}, author = {Xu, Xunnong and Gullans, Michael and Taylor, Jacob M.} } @article { ISI:000353683500008, title = {Quantum teleportation between moving detectors}, journal = {PHYSICAL REVIEW D}, volume = {91}, number = {8}, year = {2015}, month = {APR 30}, issn = {1550-7998}, doi = {10.1103/PhysRevD.91.084063}, author = {Lin, Shih-Yuin and Chou, Chung-Hsien and Hu, B. L.} } @article {2393, title = {Quantum chaos in ultracold collisions of gas-phase erbium atoms}, journal = {Nature}, volume = {507}, year = {2014}, month = {3/2014}, pages = {475-479}, doi = {10.1038/nature13137}, author = {Frisch, Albert and Mark, Michael and Aikawa, Kiyotaka and Francesca Ferlaino and Makrides, Constantinos and Petrov, Alexander and Svetlana Kotochigova} } @article { ISI:000332850800007, title = {Quantum control of qubits and atomic motion using ultrafast laser pulses}, journal = {APPLIED PHYSICS B-LASERS AND OPTICS}, volume = {114}, number = {1-2}, year = {2014}, month = {JAN}, pages = {45-61}, issn = {0946-2171}, doi = {10.1007/s00340-013-5717-6}, author = {J Mizrahi and B Neyenhuis and K G Johnson and W. C. Campbell and Crystal Senko and David Hayes and Christopher Monroe} } @article { ISI:000343225200007, title = {QUANTUM GASES The high-symmetry switch}, journal = {NATURE PHYSICS}, volume = {10}, number = {10}, year = {2014}, month = {OCT}, pages = {708-709}, issn = {1745-2473}, doi = {10.1038/nphys3107}, author = {Gorshkov, Alexey V.} } @article {2722, title = {Quantum gates with phase stability over space and time}, journal = {Phys. Rev. A}, volume = {90}, year = {2014}, month = {Oct}, pages = {042316}, doi = {10.1103/PhysRevA.90.042316}, url = {http://link.aps.org/doi/10.1103/PhysRevA.90.042316}, author = {Inlek, I. V. and Vittorini, G. and Hucul, D. and Crocker, C. and C. Monroe} } @article { ISI:000345247900007, title = {Quantum multicriticality in bilayer graphene with a tunable energy gap}, journal = {PHYSICAL REVIEW B}, volume = {90}, number = {20}, year = {2014}, month = {NOV 7}, issn = {1098-0121}, doi = {10.1103/PhysRevB.90.205407}, author = {Throckmorton, Robert E. and S. Das Sarma} } @article {2564, title = {Quantum mutual information of an entangled state propagating through a fast-light medium}, journal = {Nature Photonics}, year = {2014}, month = {5/2014}, doi = {10.1038/nphoton.2014.112}, author = {Jeremy B Clark and Ryan T Glasser and Quentin Glorieux and Vogl, Ulrich and Li, Tian and Kevin M Jones and Paul D Lett} } @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:000344056800005, title = {Quantum Phases of the Shastry-Sutherland Kondo Lattice: Implications for the Global Phase Diagram of Heavy-Fermion Metals}, journal = {PHYSICAL REVIEW LETTERS}, volume = {113}, number = {17}, year = {2014}, month = {OCT 24}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.113.176402}, author = {Pixley, J. H. and Yu, Rong and Si, Qimiao} } @article { ISI:000343735800007, title = {Quantum-defect model of a reactive collision at finite temperature}, journal = {PHYSICAL REVIEW A}, volume = {90}, number = {4}, year = {2014}, month = {OCT 10}, issn = {1050-2947}, doi = {10.1103/PhysRevA.90.042705}, author = {Jachymski, Krzysztof and Krych, Michal and Julienne, Paul S. and Idziaszek, Zbigniew} } @article { ISI:000338039400007, title = {Quasiclassical Eilenberger theory of the topological proximity effect in a superconducting nanowire}, journal = {PHYSICAL REVIEW B}, volume = {89}, number = {17}, year = {2014}, month = {MAY 30}, issn = {1098-0121}, doi = {10.1103/PhysRevB.89.174521}, author = {Stanev, Valentin and Victor M Galitski} } @article { ISI:000333410700006, title = {Quenched binary Bose-Einstein condensates: Spin-domain formation and coarsening}, journal = {Phys. Rev. A}, volume = {89}, number = {3}, year = {2014}, month = {MAR 25}, issn = {1050-2947}, doi = {10.1103/PhysRevA.89.033631}, author = {Subhadeep De and Daniel L Campbell and Ryan M. Price and Andika Putra and Brandon M Anderson and Ian B Spielman} } @article {ISI:000313938900013, title = {Quadrature interferometry for nonequilibrium ultracold atoms in optical lattices}, journal = {Phys. Rev. A}, volume = {87}, number = {1}, year = {2013}, month = {jan}, pages = {013423}, abstract = {We develop an interferometric technique for making time-resolved measurements of field-quadrature operators for nonequilibrium ultracold bosons in optical lattices. The technique exploits the internal state structure of magnetic atoms to create two subsystems of atoms in different spin states and lattice sites. A Feshbach resonance turns off atom-atom interactions in one spin subsystem, making it a well-characterized reference state, while atoms in the other subsystem undergo nonequilibrium dynamics for a variable hold time. Interfering the subsystems via a second beam-splitting operation, time-resolved quadrature measurements on the interacting atoms are obtained by detecting relative spin populations. The technique can provide quadrature measurements for a variety of Hamiltonians and lattice geometries (e. g., cubic, honeycomb, superlattices), including systems with tunneling, spin-orbit couplings using artificial gauge fields, and higher-band effects. Analyzing the special case of a deep lattice with negligible tunneling, we obtain the time evolution of both quadrature observables and their fluctuations. As a second application, we show that the interferometer can be used to measure atom-atom interaction strengths with super-Heisenberg scaling (n) over bar (-3/2) in the mean number of atoms per lattice site, and standard quantum limit scaling M-1/2 in the number of lattice sites. In our analysis, we require M \>\> 1 and for realistic systems (n) over bar is small, and therefore the scaling in total atom number N = (n) over barM is below the Heisenberg limit; nevertheless, measurements testing the scaling behaviors for interaction-based quantum metrologies should be possible in this system. DOI: 10.1103/PhysRevA.87.013423

}, issn = {1050-2947}, doi = {10.1103/PhysRevA.87.013423}, author = {Eite Tiesinga and Philip R Johnson} } @article { ISI:000324232600003, title = {Quantum Catalysis of Magnetic Phase Transitions in a Quantum Simulator}, journal = {Phys. Rev. Lett.}, volume = {111}, number = {10}, year = {2013}, month = {SEP 5}, pages = {100506}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.111.100506}, author = {Phil Richerme and Crystal Senko and Simcha Korenblit and J Smith and A Lee and Rajibul Islam and W C Campbell and Christopher Monroe} } @article { ISI:000326078100006, title = {Quantum Cherenkov radiation and noncontact friction}, journal = {PHYSICAL REVIEW A}, volume = {88}, number = {4}, year = {2013}, month = {OCT 21}, issn = {1050-2947}, doi = {10.1103/PhysRevA.88.042509}, author = {Maghrebi, Mohammad F. and Golestanian, Ramin and Kardar, Mehran} } @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} } @conference { ISI:000336029200008, title = {Quantum Networks with Atoms and Photons}, booktitle = {21ST INTERNATIONAL CONFERENCE ON LASER SPECTROSCOPY - ICOLS 2013}, series = {Journal of Physics Conference Series}, volume = {467}, year = {2013}, note = {21st International Conference on Laser Spectroscopy (ICOLS), Univ Calif, Berkeley, CA, JUN 09-14, 2013}, issn = {1742-6588}, doi = {10.1088/1742-6596/467/1/012008}, author = {C. Monroe and Campbell, W. and Cao, C. and Choi, T. and Clark, S. and Debnath, S. and Figgatt, C. and Hayes, D. and Hucul, D. and Inlek, V. and Islam, R. and Korenblit, S. and Johnson, K. and Manning, A. and Mizrahi, J. and Neyenhuis, B. and Lee, A. and Richerme, P. and C. Senko and Smith, J. and Wright, K.} } @article { ISI:000319384400007, title = {Quantum Theory of Reactive Collisions for 1/r(n) Potentials}, journal = {Phys. Rev. Lett.}, volume = {110}, number = {21}, year = {2013}, month = {MAY 23}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.213202}, author = {Jachymski, Krzysztof and Krych, Michal and Paul S Julienne and Idziaszek, Zbigniew} } @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:000306924500011, title = {Quantum decoherence of the central spin in a sparse system of dipolar coupled spins}, journal = {PHYSICAL REVIEW B}, volume = {86}, number = {3}, year = {2012}, month = {JUL 30}, issn = {1098-0121}, doi = {10.1103/PhysRevB.86.035452}, author = {Witzel, Wayne M. and Carroll, Malcolm S. and Cywinski, Lukasz and S. Das Sarma} } @article {ISI:000312830400001, title = {Quantum dynamics of disordered bosons in an optical lattice}, journal = {Phys. Rev. B}, volume = {86}, number = {21}, year = {2012}, month = {dec}, pages = {214207}, issn = {1098-0121}, doi = {10.1103/PhysRevB.86.214207}, author = {Chien-Hung Lin and Sensarma, Rajdeep and K Sengupta and S. Das Sarma} } @article {2454, title = {Quantum Interface between an Electrical Circuit and a Single Atom}, journal = {Phys. Rev. Lett.}, volume = {108}, year = {2012}, month = {3/2012}, pages = {130504}, doi = {10.1103/PhysRevLett.108.130504}, author = {D, Kielpinski and D. Kafri and M. J. Woolley and G. J. Milburn and Jacob M Taylor} } @article {Yang2012, title = {Quantum phases of disordered flatband lattice fractional quantum Hall systems}, journal = {Phys. Rev. B}, volume = {85}, number = {20}, year = {2012}, month = {may}, pages = {205124}, keywords = {Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v85/i20/e205124}, author = {Yang, Shuo and Kai Sun and S. Das Sarma} } @article {2543, title = {Quantum phases of hard-core bosons in a frustrated honeycomb lattice}, journal = {NEW JOURNAL OF PHYSICS}, volume = {14}, year = {2012}, month = {NOV 29}, pages = {115028}, issn = {1367-2630}, doi = {10.1088/1367-2630/14/11/115028}, author = {Varney, C. N. and Sun, K. and Victor M Galitski and Rigol, M.} } @article {2540, title = {Quantum simulation of spin models on an arbitrary lattice with trapped ions}, journal = {NEW JOURNAL OF PHYSICS}, volume = {14}, year = {2012}, month = {SEP 27}, pages = {095024}, issn = {1367-2630}, doi = {10.1088/1367-2630/14/9/095024}, author = {Korenblit, S. and D. Kafri and Campbell, W. C. and Islam, R. and Edwards, E. E. and Gong, Z-X and Lin, G-D and Duan, L-M and Kim, J. and Kim, K. and C. Monroe} } @article { ISI:000307441600014, title = {Quasiparticles, plasmarons, and quantum spectral function in bilayer graphene (vol 84, 041408, 2011)}, journal = {PHYSICAL REVIEW B}, volume = {86}, number = {7}, year = {2012}, month = {AUG 13}, issn = {1098-0121}, doi = {10.1103/PhysRevB.86.079912}, author = {Sensarma, Rajdeep and Hwang, E. H. and S. Das Sarma} } @article {ISI:000299843200014, title = {Quench-induced Mott-insulator-to-superfluid quantum phase transition}, journal = {Phys. Rev. A}, volume = {85}, number = {1}, year = {2012}, month = {jan}, pages = {013644}, abstract = {Mott-insulator-to-superfluid quenches have been used by recent experiments to generate exotic superfluid phases. While the final Hamiltonian following the sudden quench is that of a superfluid, it is not a priori clear whether the final state of the system actually enters the superfluid phase. To understand the nature of the final state the temporal evolution of the momentum distribution is calculated following a Mott-insulator-to-superfluid quench. Using the numerical infinite time-evolving block decimation approach and the analytical rotor model approximation it is established that the one- and two-dimensional Mott insulators following the quench equilibrate to thermal states with spatially short-ranged coherence peaks in the final momentum distribution and therefore are not superfluids. However, in three dimensions a divergence in the momentum distribution indicating the emergence of true superfluid order is found.

}, keywords = {2012, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v85/i1/e013644}, author = {Jay D Sau and Bin Wang and S. Das Sarma} } @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 {Kim2011a, title = {Quantum simulation of the transverse Ising model with trapped ions}, journal = {New J. Phys.}, volume = {13}, number = {10}, year = {2011}, month = {oct}, pages = {105003}, abstract = {Crystals of trapped atomic ions are among the most promising platforms for the quantum simulation of many-body quantum physics. Here, we describe recent developments in the simulation of quantum magnetic spin models with trapped 171 Yb + ions, and discuss the possibility of scaling the system to a level of complexity where classical computation becomes intractable.

}, keywords = {Multiple JQI Affil., Single Fellow}, issn = {1367-2630}, url = {http://stacks.iop.org/1367-2630/13/i=10/a=105003}, author = {K Kim and Simcha Korenblit and Rajibul Islam and Emily E Edwards and M -S Chang and Noh, C and Howard J Carmichael and G -D Lin and L M Duan and C C J Wang and J K Freericks and Christopher Monroe} } @article { ISI:000294640100003, title = {Quantum theory of the charge-stability diagram of semiconductor double-quantum-dot systems}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {11}, year = {2011}, month = {SEP 7}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.115301}, author = {Wang, Xin and Yang, Shuo and S. Das Sarma} } @article { ISI:000293921000017, title = {Quantum-Classical Crossover and Apparent Metal-Insulator Transition in a Weakly Interacting 2D Fermi Liquid}, journal = {PHYSICAL REVIEW LETTERS}, volume = {107}, number = {8}, year = {2011}, month = {AUG 16}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.107.086804}, author = {Zhou, Xiaoqing and Schmidt, B. and Proust, C. and Gervais, G. and Pfeiffer, L. N. and West, K. W. and S. Das Sarma} } @article { ISI:000293126900002, title = {Quantum-to-classical correspondence and Hubbard-Stratonovich dynamical systems: A Lie-algebraic approach}, journal = {PHYSICAL REVIEW A}, volume = {84}, number = {1}, year = {2011}, month = {JUL 26}, issn = {1050-2947}, doi = {10.1103/PhysRevA.84.012118}, author = {Victor M Galitski} } @article { ISI:000293129300001, title = {Quasiparticles, plasmarons, and quantum spectral function in bilayer graphene}, journal = {PHYSICAL REVIEW B}, volume = {84}, number = {4}, year = {2011}, month = {JUL 25}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.041408}, author = {Sensarma, Rajdeep and Hwang, E. H. and S. Das Sarma} } @article {Ladd2010, title = {Quantum computers}, journal = {Nature}, volume = {464}, number = {7285}, year = {2010}, month = {mar}, pages = {45{\textendash}53}, publisher = {Macmillan Publishers Limited. All rights reserved}, abstract = {Over the past several decades, quantum information science has emerged to seek answers to the question: can we gain some advantage by storing, transmitting and processing information encoded in systems that exhibit unique quantum properties? Today it is understood that the answer is yes, and many research groups around the world are working towards the highly ambitious technological goal of building a quantum computer, which would dramatically improve computational power for particular tasks. A number of physical systems, spanning much of modern physics, are being developed for quantum computation. However, it remains unclear which technology, if any, will ultimately prove successful. Here we describe the latest developments for each of the leading approaches and explain the major challenges for the future.

}, keywords = {2010, Single Fellow}, issn = {1476-4687}, url = {http://dx.doi.org/10.1038/nature08812}, author = {Ladd, T D and Jelezko, F and Laflamme, R and Nakamura, Y and Christopher Monroe and O{\textquoteright}Brien, J L} } @article { ISI:000282871700006, title = {Quantum dot spin qubits in silicon: Multivalley physics}, journal = {PHYSICAL REVIEW B}, volume = {82}, number = {15}, year = {2010}, month = {OCT 13}, issn = {1098-0121}, doi = {10.1103/PhysRevB.82.155312}, author = {Culcer, Dimitrie and Cywinski, Lukasz and Li, Qiuzi and Hu, Xuedong and S. Das Sarma} } @article { ISI:000277217200060, title = {Quantum Hall phase diagram of half-filled bilayers in the lowest and the second orbital Landau levels: Abelian versus non-Abelian incompressible fractional quantum Hall states}, journal = {PHYSICAL REVIEW B}, volume = {81}, number = {16}, year = {2010}, month = {APR 15}, issn = {1098-0121}, doi = {10.1103/PhysRevB.81.165304}, author = {Peterson, Michael R. and S. Das Sarma} } @article {OLMSCHENK2010, title = {Quantum Logic Between Distant Trapped Ions}, journal = {Int. J. Quant. Info.}, volume = {08}, number = {01 \& 02}, year = {2010}, month = {jul}, pages = {337}, abstract = {Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.

}, keywords = {2010}, issn = {0219-7499}, url = {http://arxiv.org/abs/0907.1702}, author = {Steven Olmschenk and David Hayes and D N Matsukevich and P Maunz and D L Moehring and Christopher Monroe} } @article {1832, title = {Quantum networks with trapped ions}, journal = {Rev. Mod. Phys.}, volume = {82}, year = {2010}, pages = {1209}, keywords = {Single Fellow}, doi = {10.1103/RevModPhys.82.1209}, url = {http://link.aps.org/doi/10.1103/RevModPhys.82.120}, author = {Christopher Monroe and L M Duan} } @article {Capogrosso-Sansone2010, title = {Quantum Phases of Cold Polar Molecules in 2D Optical Lattices}, journal = {Phys. Rev. Lett.}, volume = {104}, number = {12}, year = {2010}, month = {mar}, keywords = {2010, No Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v104/i12/e125301}, author = {Capogrosso-Sansone, B. and Trefzger, C. and Maciej Lewenstein and Peter Zoller and Guido Pupillo} } @article {Edwards2010, title = {Quantum simulation and phase diagram of the transverse-field Ising model with three atomic spins}, journal = {Phys. Rev. B}, volume = {82}, number = {6}, year = {2010}, month = {aug}, keywords = {2010, Multiple JQI Affil., Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v82/i6/e060412}, author = {Emily E Edwards and Simcha Korenblit and K Kim and Rajibul Islam and M -S Chang and J K Freericks and G -D Lin and L M Duan and Christopher Monroe} } @article {Kim2010, title = {Quantum simulation of frustrated Ising spins with trapped ions}, journal = {Nature}, volume = {465}, number = {7298}, year = {2010}, month = {jun}, pages = {590{\textendash}3}, publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.}, abstract = {A network is frustrated when competing interactions between nodes prevent each bond from being satisfied. This compromise is central to the behaviour of many complex systems, from social and neural networks to protein folding and magnetism. Frustrated networks have highly degenerate ground states, with excess entropy and disorder even at zero temperature. In the case of quantum networks, frustration can lead to massively entangled ground states, underpinning exotic materials such as quantum spin liquids and spin glasses. Here we realize a quantum simulation of frustrated Ising spins in a system of three trapped atomic ions, whose interactions are precisely controlled using optical forces. We study the ground state of this system as it adiabatically evolves from a transverse polarized state, and observe that frustration induces extra degeneracy. We also measure the entanglement in the system, finding a link between frustration and ground-state entanglement. This experimental system can be scaled to simulate larger numbers of spins, the ground states of which (for frustrated interactions) cannot be simulated on a classical computer.

}, keywords = {2010, Multiple JQI Affil., Single Fellow}, issn = {1476-4687}, url = {http://dx.doi.org/10.1038/nature09071}, author = {K Kim and M -S Chang and Simcha Korenblit and Rajibul Islam and Emily E Edwards and J K Freericks and G -D Lin and L M Duan and Christopher Monroe} } @article {2460, title = {The quantum spin Hall effect and topological insulators}, journal = {Physics Today}, volume = {63}, year = {2010}, month = {1/2010}, doi = {10.1063/1.3293411}, author = {Xiao-Liang Qi and Shou-Cheng Zhang} } @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 {Huckans2009, title = {Quantum and Classical Dynamics of a BEC in a Large-Period Optical Lattice}, journal = {Physical Review A}, volume = {80}, year = {2009}, month = {jan}, pages = {043609}, abstract = {We experimentally investigate diffraction of a Rb-87 Bose-Einstein condensate from a 1D optical lattice. We use a range of lattice periods and timescales, including those beyond the Raman-Nath limit. We compare the results to quantum mechanical and classical simulations, with quantitative and qualitative agreement, respectively. The classical simulation predicts that the envelope of the time-evolving diffraction pattern is shaped by caustics: singularities in the phase space density of classical trajectories. This behavior becomes increasingly clear as the lattice period grows.

}, keywords = {2009}, url = {http://arxiv.org/abs/0901.1386}, author = {J H Huckans and Ian B Spielman and Tolra, B. Laburthe and William D Phillips and J V Porto} } @article { ISI:000267599600011, title = {Quantum control and manipulation of donor electrons in Si-based quantum computing}, journal = {JOURNAL OF APPLIED PHYSICS}, volume = {105}, number = {12}, year = {2009}, note = {29th International Conference on Physics of Semiconductors, Rio de Janeiro, BRAZIL, JUL 27-AUG 01, 2008}, month = {JUN 15}, issn = {0021-8979}, doi = {10.1063/1.3124084}, author = {Calderon, M. J. and Saraiva, A. and Koiller, Belita and S. Das Sarma} } @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:000271351000019, title = {Quantum distillation: Dynamical generation of low-entropy states of strongly correlated fermions in an optical lattice}, journal = {PHYSICAL REVIEW A}, volume = {80}, number = {4}, year = {2009}, month = {OCT}, issn = {1050-2947}, doi = {10.1103/PhysRevA.80.041603}, author = {Heidrich-Meisner, F. and Manmana, S. R. and Rigol, M. and Muramatsu, A. and Feiguin, A. E. and Dagotto, E.} } @article {Mishmash2009, title = {Quantum many-body dynamics of dark solitons in optical lattices}, journal = {Phys. Rev. A}, volume = {80}, number = {5}, year = {2009}, month = {nov}, pages = {053612}, abstract = {We present a fully quantum many-body treatment of dark solitons formed by ultracold bosonic atoms in one-dimensional optical lattices. Using time-evolving block decimation to simulate the single-band Bose-Hubbard Hamiltonian, we consider the quantum dynamics of density and phase engineered dark solitons as well as the quantum evolution of mean-field dark solitons injected into the quantum model. The former approach directly models how one may create quantum entangled dark solitons in experiment. While we have already presented results regarding the latter approach elsewhere [Phys. Rev. Lett. \{$\backslash$bf 103\}, 140403 (2009)], we expand upon those results in this work. In both cases, quantum fluctuations cause the dark soliton to fill in and may induce an inelasticity in soliton-soliton collisions. Comparisons are made to the Bogoliubov theory which predicts depletion into an anomalous mode that fills in the soliton. Our many-body treatment allows us to go beyond the Bogoliubov approximation and calculate explicitly the dynamics of the system{\textquoteright}s natural orbitals.

}, keywords = {2009, Single Fellow}, issn = {1050-2947}, url = {http://arxiv.org/abs/0906.4949 http://pra.aps.org/abstract/PRA/v80/i5/e053612}, author = {Mishmash, R. and Ippei Danshita and Charles W Clark and L D Carr} } @article { ISI:000266500900015, title = {Quantum phase diagram of fermion mixtures with population imbalance in one-dimensional optical lattices}, journal = {PHYSICAL REVIEW A}, volume = {79}, number = {5}, year = {2009}, month = {MAY}, issn = {1050-2947}, doi = {10.1103/PhysRevA.79.051604}, author = {Wang, B. and Chen, Han-Dong and S. Das Sarma} } @article {Liu2009a, title = {Quantum Phase Transitions and Continuous Observation of Spinor Dynamics in an Antiferromagnetic Condensate}, journal = {Phys. Rev. Lett.}, volume = {102}, number = {12}, year = {2009}, month = {mar}, pages = {125301}, keywords = {2009}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v102/i12/e125301}, author = {Liu, Y. and Jung, S. and Maxwell, S. and L D Turner and Eite Tiesinga and Paul D Lett} } @article {Polyakov2009, title = {Quantum radiometry}, journal = {Journal of Modern Optics}, volume = {56}, number = {9}, year = {2009}, month = {may}, pages = {1045{\textendash}1052}, publisher = {Taylor \& Francis}, abstract = {We review radiometric techniques that take advantage of photon counting and stem from the quantum laws of nature. We present a brief history of metrological experiments and review the current state of experimental quantum radiometry. We review radiometric techniques that take advantage of photon counting and stem from the quantum laws of nature. We present a brief history of metrological experiments and review the current state of experimental quantum radiometry.}, keywords = {2009}, issn = {0950-0340}, url = {http://dx.doi.org/10.1080/09500340902919477}, author = {Sergey V Polyakov and Alan L Migdall} } @article {Olmschenk2009a, title = {Quantum teleportation between distant matter qubits}, journal = {Science}, volume = {323}, number = {5913}, year = {2009}, month = {jan}, pages = {486{\textendash}9}, abstract = {Quantum teleportation is the faithful transfer of quantum states between systems, relying on the prior establishment of entanglement and using only classical communication during the transmission. We report teleportation of quantum information between atomic quantum memories separated by about 1 meter. A quantum bit stored in a single trapped ytterbium ion (Yb+) is teleported to a second Yb+ atom with an average fidelity of 90\% over a replete set of states. The teleportation protocol is based on the heralded entanglement of the atoms through interference and detection of photons emitted from each atom and guided through optical fibers. This scheme may be used for scalable quantum computation and quantum communication.

}, keywords = {2009, Single Fellow}, issn = {1095-9203}, url = {http://www.sciencemag.org/content/323/5913/486.abstract}, author = {Steven Olmschenk and D N Matsukevich and P Maunz and David Hayes and L M Duan and Christopher Monroe} } @article {Idziaszek2009, title = {Quantum theory of ultracold atom-ion collisions}, journal = {Phys. Rev. A}, volume = {79}, number = {1}, year = {2009}, month = {jan}, keywords = {2009}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v79/i1/e010702}, author = {Idziaszek, Zbigniew and Tommaso Calarco and Paul S Julienne and Simoni, Andrea} } @article {Court2008, title = {Quantitative study of quasiparticle traps using the single-Cooper-pair transistor}, journal = {Phys. Rev. B}, volume = {77}, number = {10}, year = {2008}, month = {mar}, keywords = {2008, No Fellows}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v77/i10/e100501}, author = {Court, N. and Ferguson, A. and Roman M Lutchyn and R J Clark} } @article {Mitra2008, title = {Quantum behavior of a dc SQUID phase qubit}, journal = {Phys. Rev. B}, volume = {77}, number = {21}, year = {2008}, month = {jun}, keywords = {2008, CMAMO, Multiple Fellows}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v77/i21/e214512}, author = {Kaushik Mitra and Frederick W Strauch and Christopher J Lobb and Jeffrey R Anderson and F C Wellstood and Eite Tiesinga} } @article {C.Monroe2008a, title = {Quantum Computing with Ions}, journal = {Scientific American}, year = {2008}, pages = {64{\textendash}71}, keywords = {2008, Single Fellow}, author = {Christopher Monroe and David J Wineland} } @article {Lutchyn2008a, title = {Quantum decoherence of a charge qubit in a spin-fermion model}, journal = {Phys. Rev. B}, volume = {78}, number = {2}, year = {2008}, month = {jul}, keywords = {2008, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v78/i2/e024508}, author = {Roman M Lutchyn and {\L}ukasz Cywi{\'n}ski and Nave, Cody and S. Das Sarma} } @article {springerlink:10.1134/S1054660X08030213, title = {Quantum phase transition of ultracold bosons in double-well optical lattices}, journal = {Laser Physics}, volume = {18}, number = {3}, year = {2008}, pages = {318{\textendash}321}, publisher = {MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.}, keywords = {2008, Single Fellow}, issn = {1054-660X}, url = {http://dx.doi.org/10.1134/S1054660X08030213}, author = {Ippei Danshita and James E Williams and de Melo, C and Charles W Clark} } @article {Hwang2008a, title = {Quasiparticle spectral function in doped graphene: Electron-electron interaction effects in ARPES}, journal = {Phys. Rev. B}, volume = {77}, number = {8}, year = {2008}, month = {feb}, keywords = {2008, Single Fellow}, issn = {1098-0121}, url = {http://prb.aps.org/abstract/PRB/v77/i8/e081412}, author = {E H Hwang and S. Das Sarma} } @article {Tewari2007a, title = {Quantum computation using vortices and majorana zero modes of a px + ipy superfluid of fermionic cold atoms}, journal = {Phys. Rev. Lett.}, volume = {98}, number = {1}, year = {2007}, month = {jan}, pages = {010506}, abstract = {We propose to use the recently predicted two-dimensional "weak-pairing" px + ipy superfluid state of fermionic cold atoms as a platform for topological quantum computation. In the core of a vortex, this state supports a zero-energy Majorana mode, which moves to finite energy in the corresponding topologically trivial "strong-pairing" state. By braiding vortices in the "weak-pairing" state, unitary quantum gates can be applied to the Hilbert space of Majorana zero modes. For readout of the topological qubits, we propose realistic schemes suitable for atomic superfluids.}, keywords = {2007, Single Fellow}, issn = {0031-9007}, url = {http://www.ncbi.nlm.nih.gov/pubmed/17358465}, author = {Tewari, Sumanta and S. Das Sarma and Chetan Nayak and Zhang, Chuanwei and Peter Zoller} } @conference { ISI:000246281800538, title = {Quantum control of donor-bound electrons at the Si-SiO2 interface}, booktitle = {Physics of Semiconductors, Pts A and B}, series = {AIP CONFERENCE PROCEEDINGS}, volume = {893}, year = {2007}, note = {28th International Conference on the Physics of Semiconductors (ICPS-28), Vienna, AUSTRIA, JUL 24-28, 2006}, pages = {1095-1096}, isbn = {978-0-7354-0397-0}, issn = {0094-243X}, author = {Koiller, Belita and Calderon, M. J. and Hu, Xuedong and S. Das Sarma}, editor = {Jantsch, W and Schaffler, F} } @article {Danshita2007, title = {Quantum phases of bosons in double-well optical lattices}, journal = {Phys. Rev. A}, volume = {76}, number = {4}, year = {2007}, month = {oct}, keywords = {2007, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v76/i4/e043606}, author = {Ippei Danshita and James E Williams and C A R S{\'a} de Melo and Charles W Clark} } @article {Mellish2007, title = {Quantum scattering of distinguishable bosons using an ultracold-atom collider}, journal = {Phys. Rev. A}, volume = {75}, number = {2}, year = {2007}, month = {feb}, keywords = {2007, Single Fellow}, issn = {1050-2947}, url = {http://pra.aps.org/abstract/PRA/v75/i2/e020701}, author = {Mellish, Angela and Kj{\ae} rgaard, Niels and Paul S Julienne and Wilson, Andrew} } @article {Andersen2006, title = {Quantized Rotation of Atoms from Photons with Orbital Angular Momentum}, journal = {Phys. Rev. Lett.}, volume = {97}, number = {17}, year = {2006}, pages = {170406}, keywords = {2006, Multiple Fellows}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v97/i17/e170406}, author = {Andersen, M.F. and Changhyun Ryu and Pierre Clad{\'e} and Vasant Natarajan and Alipasha Vaziri and Kristian Helmerson and William D Phillips} } @article {Rey2006, title = {Quantum coherence of Hard-Core-Bosons and Fermions: Extended, Glassy and Mott Phases}, journal = {J. Phys. B: At. Mol. Opt. Phys.}, volume = {-1}, number = {8}, year = {2006}, month = {may}, pages = {3004}, abstract = {Noise correlations, such as those observable in the time of flight images of a released cloud, are calculated for hard-core bosonic (HCBs) atoms. These second-order correlations are used to explore quantum coherence of strongly correlated bosons in the fermionized regime with and without external parabolic confinement. Our analysis points to distinctive new experimental signatures of the Mott phase. We also calculate noise correlations for the corresponding spin-1/2 XY model onto which the HCB system is standardly mapped. Our study shows important differences between the two systems due to the contribution of multiply occupied virtual states in HCBs. Such states do not exist in spin models. An interesting manifestation of such states is the breaking of particle{\textendash}hole symmetry in HCB systems.}, keywords = {2006, Single Fellow}, issn = {1367-2630}, url = {http://stacks.iop.org/0953-4075/39/i=10/a=S17 http://adsabs.harvard.edu/abs/2006APS..DMP.N3004R http://arxiv.org/abs/cond-mat/0604154}, author = {A M Rey and Indubala Satija and Charles W Clark} } @article { ISI:000235905700051, title = {Quantum control of donor electrons at the Si-SiO2 interface}, journal = {PHYSICAL REVIEW LETTERS}, volume = {96}, number = {9}, year = {2006}, month = {MAR 10}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.96.096802}, author = {Calderon, MJ and Koiller, B and Hu, XD and S. Das Sarma} } @article {Deng2006, title = {Quantum Degenerate Exciton-Polaritons in Thermal Equilibrium}, journal = {Phys. Rev. Lett.}, volume = {97}, number = {14}, year = {2006}, month = {oct}, abstract = {We study the momentum distribution and relaxation dynamics of semiconductor microcavity polaritons by angle-resolved and time-resolved spectroscopy. Above a critical pump level, the thermalization time of polaritons at positive detunings becomes shorter than their lifetime, and the polaritons form a quantum degenerate Bose-Einstein distribution in thermal equilibrium with the lattice.}, keywords = {2006, Single Fellow}, issn = {0031-9007}, url = {http://arxiv.org/abs/cond-mat/0604394}, author = {Deng, Hui and Press, David and Stephan G{\"o}tzinger and Glenn S Solomon and Hey, Rudolf and Ploog, Klaus and Yoshihisa Yamamoto} } @article {Hayes2006, title = {Quantum logic via the exchange blockade in ultracold collisions}, year = {2006}, month = {sep}, abstract = {A nuclear spin can act as a quantum switch that turns on or off ultracold collisions between atoms even when there is neither interaction between nuclear spins nor between the nuclear and electron spins. This "exchange blockade" is a new mechanism for implementing quantum logic gates that arises from the symmetry of composite identical particles, rather than direct coupling between qubits. We study the implementation of the entangling \$\backslash sqrt\{\backslash text\{SWAP\}\}\$ gate based on this mechanism for a model system of two atoms with ground electron configuration \$\^{}1S\_0\$, spin 1/2 nuclei, trapped in optical tweezers. We evaluate a proof-of-principle protocol based on adiabatic evolution of a one dimensional double Gaussian well, calculating fidelities of operation as a function of interaction strength, gate time, and temperature.}, keywords = {2006, Single Fellow}, url = {http://arxiv.org/abs/quant-ph/0609111}, author = {David Hayes and Paul S Julienne and Deutsch, Ivan} } @article {Wu2006, title = {Quantum Stripe Ordering in Optical Lattices}, journal = {Phys. Rev. Lett.}, volume = {97}, number = {19}, year = {2006}, month = {nov}, keywords = {2006, Single Fellow}, issn = {0031-9007}, url = {http://prl.aps.org/abstract/PRL/v97/i19/e190406}, author = {Wu, Congjun and W V Liu and Moore, Joe and S. Das Sarma} } @article { ISI:000239426700087, title = {Quantum theory for electron spin decoherence induced by nuclear spin dynamics in semiconductor quantum computer architectures: Spectral diffusion of localized electron spins in the nuclear solid-state environment}, journal = {PHYSICAL REVIEW B}, volume = {74}, number = {3}, year = {2006}, month = {JUL}, issn = {1098-0121}, doi = {10.1103/PhysRevB.74.035322}, author = {Witzel, W. M. and S. Das Sarma} }