Kharkiv Quantum Seminar: 2023 November 14, 16:00 (EET)

IBM’s experiment on quantum utility before fault tolerance and its implications

Kyrylo Snizhko (CEA Grenoble, France;

the quantum work group of Ukrainian Physical Society, qUA)

Full-fledged quantum computing will require extensive use of quantum error correction techniques. While these are believed to be within reach, in principle, practical implementations require numerous engineering advances and are thus a matter of distant future. In the meantime, investigations of the capabilities of so-called noisy intermediate-scale quantum (NISQ) devices are actively underway.

Last summer, an experiment from IBM Quantum [1] has shaken the community: simulation of a quantum system beyond the capabilities of classical calculations was claimed. I will review this experiment, as well as a number of follow-up theoretical works [2-6] in order to provide the insight into the current capabilities of NISQ devices.

[1] Y. Kim et al., “Evidence for the utility of quantum computing before fault tolerance,” Nature 618, 500 (2023).

[2] J. Tindall, M. Fishman, M. Stoudenmire, and D. Sels, “Efficient tensor network simulation of IBM’s kicked Ising experiment,” arXiv:2306.14887.

[3] K. Kechedzhi et al., “Effective quantum volume, fidelity and computational cost of noisy quantum processing experiments,” arXiv:2306.15970.

[4] T. Begušić and G. K.-L. Chan, “Fast classical simulation of evidence for the utility of quantum computing before fault tolerance,” arXiv:2306.16372.

[5] E. G. D. Torre and M. M. Roses, “Dissipative mean-field theory of IBM utility experiment,” arXiv:2308.01339.

[6] S. Patra, S. S. Jahromi, S. Singh, and R. Orus, “Efficient tensor network simulation of IBM’s largest quantum processors,” arXiv:2309.15642.