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arXiv · 2212.11632

Performance enhancement of surface codes via recursive MWPM decoding

Antonio deMarti iOlius·Josu Etxezarreta Martinez·Patricio Fuentes·Pedro M. Crespo
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Abstract

The minimum weight perfect matching (MWPM) decoder is the standard decoding strategy for quantum surface codes. However, it suffers a harsh decrease in performance when subjected to biased or non-identical quantum noise. In this work, we modify the conventional MWPM decoder so that it considers the biases, the non-uniformities and the relationship between $X$, $Y$ and $Z$ errors of the constituent qubits of a given surface code. Our modified approach, which we refer to as the recursive MWPM decoder, obtains an $18\%$ improvement in the probability threshold $p_{th}$ under depolarizing noise. We also obtain significant performance improvements when considering biased noise and independent non-identically distributed (i.ni.d.) error models derived from measurements performed on state-of-the-art quantum processors. In fact, when subjected to i.ni.d. noise, the recursive MWPM decoder yields a performance improvement of $105.5\%$ over the conventional MWPM strategy and, in some cases, it even surpasses the performance obtained over the well-known depolarizing channel.

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Antonio deMarti iOlius, Josu Etxezarreta Martinez, Patricio Fuentes, Pedro M. Crespo. 2022-12-22. Performance enhancement of surface codes via recursive MWPM decoding. https://doi.org/10.1103/physreva.108.022401

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