@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: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.}
}