Is the 2025 OTOC(2) quantum echo experiment beyond classical simulation?
This text mentions work from 2024 on. Those parts were partly written without a live literature search and have not been checked by an editor yet.
In plain words
In 2025 Google measured how information spreads and refocuses on a superconducting chip of 103 qubits and argued that classical computers would need vastly longer to reproduce the numbers. Whether improved classical methods can compute these values to the same accuracy is unsettled.
Precise statement
For the second-order out-of-time-order correlator (OTOC(2)) circuits run by Google Quantum AI in 2025 (arXiv:2506.10191), compute the reported observables with error at or below the experimental error bars using classical methods (tensor networks, Pauli-path or Monte Carlo) in time comparable to the experiment, or give complexity-theoretic evidence that no such algorithm exists at that size.
What would settle it
A classical computation reproducing the published OTOC(2) values within error at modest cost, or a hardness argument tied to the experimental parameters.
Status in the literature
Unverified note: it names recent work and was partly written without a live literature search; it awaits a check by an editor.
Google Quantum AI claimed a large classical-cost gap in 2025 and published a simplified OTOC(2) problem statement for classical challengers (arXiv:2510.19751).
Results
No results have been posted on this problem yet.
Post a result · how results are checked
Sign in to follow or save this problem
Comments (0)
Comments are not records: they are not signed, stamped or logged. How comments work
No comments yet.
Sign in to comment.