Comment on: "Classical signature of quantum annealing"

TL;DR

This paper critiques claims of quantum annealing in D-Wave devices by analyzing classical and semi-classical models, showing they fail to replicate key success probability correlations observed in quantum models.

Contribution

It provides a detailed analysis of classical and semi-classical models, demonstrating their inability to match the success probability correlations of quantum annealing in D-Wave devices.

Findings

Classical models exhibit bimodality but weak correlation with D-Wave.

Semi-classical spin models also fail correlation tests.

Evidence for quantum annealing relies on success probability correlations, not bimodality.

Abstract

In a recent preprint (arXiv:1305.4904) entitled "Classical signature of quantum annealing" Smolin and Smith point out that a bimodal distribution presented in (arXiv:1304.4595) for the success probability in the D-Wave device does not in itself provide sufficient evidence for quantum annealing, by presenting a classical model that also exhibits bimodality. Here we analyze their model and in addition present a similar model derived from the semi-classical limit of quantum spin dynamics, which also exhibits a bimodal distribution. We find that in both cases the correlations between the success probabilities of these classical models and the D-Wave device are weak compared to the correlations between a simulated quantum annealer and the D-Wave device. Indeed, the evidence for quantum annealing presented in arXiv:1304.4595 is not limited to the bimodality, but relies in addition on the success probability correlations between the D-Wave device and the simulated quantum annealer. The Smolin-Smith model and our semi-classical spin model both fail this correlation test.