We verify that the quantum processor is working properly using amethod called cross-entropy benchmarking11,12,14, which compares howoften each bitstring is observed experimentally with its correspondingideal probability computed via simulation on a classical computer. Fora given circuit, we collect the measured bitstrings {xi} and compute thelinear cross-entropy benchmarking fidelity11,13,14 (see also SupplementaryInformation), which is the mean of the simulated probabilities of thebitstrings we measured: