Fig. 3: Benchmarks against the ground truth.
From: Quantum computational advantage with a programmable photonic processor
a, Cross-entropy benchmark against the ground truth. Experimental samples from a high-dimensional GBS instance of 216 modes, averaging \(\bar{N}=21.120\pm 0.006\) photons per sample, are bundled according to their total photon number N, from 10 to 26. Each point (score) corresponds to an average (equation (1)) over 10,000 samples per N. Genuine samples from the quantum hardware score higher than all classical spoofers, validating the high device fidelity with the ground truth. Error bars are standard errors of the mean. b, Bayesian log average score against the ground truth. Experimental samples from a 72-mode GBS instance and \(\bar{N}=22.416\pm 0.006\) photon number per sample. Each score is averaged over 2,000 samples with N from 10 to 26. Error bars are standard errors of the mean. All scores are above zero, including error bar, indicating that the samples generated by Borealis are closer to the ground truth than from the adversarial distribution corresponding to squashed, thermal, coherent and distinguishable squeezed spoofers.
