Unbiased simulation of near-Clifford quantum circuits

Journal Article · Wed Jun 28 04:00:00 UTC 2017 · Physical Review A

DOI: https://doi.org/10.1103/PhysRevA.95.062337 · OSTI ID:1376419

Bennink, Ryan S. ^[1]; Ferragut, Erik M. ^[1]; Humble, Travis S. ^[1]; Laska, Jason A. ^[1]; Nutaro, James J. ^[1]; Pleszkoch, Mark G. ^[1]; Pooser, Raphael C. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Quantum Computing Inst.

Modeling and simulation are essential for predicting and verifying the behavior of fabricated quantum circuits, but existing simulation methods are either impractically costly or require an unrealistic simplification of error processes. In this paper, we present a method of simulating noisy Clifford circuits that is both accurate and practical in experimentally relevant regimes. In particular, the cost is weakly exponential in the size and the degree of non-Cliffordness of the circuit. Our approach is based on the construction of exact representations of quantum channels as quasiprobability distributions over stabilizer operations, which are then sampled, simulated, and weighted to yield unbiased statistical estimates of circuit outputs and other observables. As a demonstration of these techniques, we simulate a Steane [[7,1,3]]-encoded logical operation with non-Clifford errors and compute its fault tolerance error threshold. Finally, we expect that the method presented here will enable studies of much larger and more realistic quantum circuits than was previously possible.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; Intelligence Advanced Research Projects Activity (IARPA) (United States)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1376419
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 6 Vol. 95; ISSN 2469-9926
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English