We demonstrate that the performance of a quantum annealer on hard random Ising optimization problems can be substantially improved using quantum annealing correction (QAC). Our error correction strategy is tailored to the D-Wave Two device. We find that QAC provides a statistically significant enhancement in the performance of the device over a classical repetition code, improving as a function of problem size as well as hardness. Moreover, QAC provides a mechanism for overcoming the precision limit of the device, in addition to correcting calibration errors. Performance is robust even to missing qubits. We present evidence for a constructive role played by quantum effects in our experiments by contrasting the experimental results with the predictions of a classical model of the device. Our work demonstrates the importance of error correction in appropriately determining the performance of quantum annealers.
@article{arxiv.1408.4382,
title = {Quantum annealing correction for random Ising problems},
author = {Kristen L. Pudenz and Tameem Albash and Daniel A. Lidar},
journal= {arXiv preprint arXiv:1408.4382},
year = {2015}
}
Comments
17 pages, 14 figures. v2: updated to published version