Comparison of quantum advantage experiments using random circuit sampling

Journal Article · Mon Feb 13 00:00:00 EST 2023 · Physical Review A

DOI:https://doi.org/10.1103/physreva.107.022610· OSTI ID:2425052

Oh, Sangchul ^[1]; Kais, Sabre ^[1]

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1. Purdue University, West Lafayette, IN (United States)

Random circuit sampling, the task of sampling bit strings from a random unitary operator, has been implemented to demonstrate quantum advantage on the Sycamore quantum processor with 53 qubits and on the Zuchongzhi quantum processor with 56 and 61 qubits. Recently, it was claimed that classical computers using tensor network simulation could catch on to current noisy quantum processors for random circuit sampling. While the linear cross-entropy benchmark fidelity was used to certify all these claims, it may not capture statistical properties of outputs in detail. Here, we compare the bit strings sampled from classical computers using tensor network simulation by Pan et al. [F. Pan, K. Chen, and P. Zhang, Phys. Rev. Lett. 129, 090502 (2022)] and by Kalachev et al. [G. Kalachev, P. Panteleev, P. Zhou, and M.-H. Yung, arXiv:2112.15083] with the bit strings from the Sycamore quantum processor. It is shown that all of Kalachev et al.'s samples passed the NIST random number tests. The heat maps of bit strings show that Pan et al.'s and Kalachev et al.'s samples are quite different from the Sycamore or Zuchongzhi samples. The analysis with the Marchenko-Pastur distribution and the Wasssertein distances demonstrates that Kalachev et al.'s samples are statistically closer to the Sycamore samples than Pan et al.'s while the three datasets have similar values for the linear cross-entropy fidelity. In conclusion, our finding implies that further study is needed to certify or beat the claims of quantum advantage using random circuit sampling.

• Research Organization: National Quantum Information Science (QIS) Research Centers (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC)
• OSTI ID: 2425052
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 2 Vol. 107; ISSN 2469-9926
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Optics
Physics
Quantum algorithms
Quantum benchmarking
Quantum circuits
Quantum simulation
Quantum verification