Classical Simulation of Intermediate-Size Quantum Circuits [article]

Jianxin Chen, Fang Zhang, Cupjin Huang, Michael Newman, Yaoyun Shi
2018 arXiv   pre-print
We introduce a distributed classical simulation algorithm for general quantum circuits, and present numerical results for calculating the output probabilities of universal random circuits. We find that we can simulate more qubits to greater depth than previously reported using the cluster supported by the Data Infrastructure and Search Technology Division of the Alibaba Group. For example, computing a single amplitude of an 8× 8 qubit circuit with depth 40 was previously beyond the reach of
more » ... rcomputers. Our algorithm can compute this within 2 minutes using a small portion (≈ 14 nodes) of the cluster. Furthermore, by successfully simulating quantum supremacy circuits of size 9× 9× 40, 10× 10× 35 , 11× 11× 31, and 12× 12× 27 , we give evidence that noisy random circuits with realistic physical parameters may be simulated classically. This suggests that either harder circuits or error-correction may be vital for achieving quantum supremacy from random circuit sampling.
arXiv:1805.01450v2 fatcat:zd5ebgxowfcofauhwtte2r2ssi