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arXiv · 2401.12434

Efficient near-optimal decoding of the surface code through ensembling

Noah Shutty·Michael Newman·Benjamin Villalonga
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Abstract

We introduce harmonization, an ensembling method that combines several "noisy" decoders to generate highly accurate decoding predictions. Harmonized ensembles of MWPM-based decoders achieve lower logical error rates than their individual counterparts on repetition and surface code benchmarks, approaching maximum-likelihood accuracy at large ensemble sizes. We can use the degree of consensus among the ensemble as a confidence measure for a layered decoding scheme, in which a small ensemble flags high-risk cases to be checked by a larger, more accurate ensemble. This layered scheme can realize the accuracy improvements of large ensembles with a relatively small constant factor of computational overhead. We conclude that harmonization provides a viable path towards highly accurate real-time decoding.

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Noah Shutty, Michael Newman, Benjamin Villalonga. 2024-01-23. Efficient near-optimal decoding of the surface code through ensembling. https://arxiv.org/abs/2401.12434

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