Correcting non-Pauli noise with detector error models estimated from syndrome measurements
Phys. Rev. A 114, 022449 – Published 24 August, 2026
DOI: https://doi.org/10.1103/s46l-pnlq
Abstract
Decoders of quantum error correction (QEC) experiments make decisions based on detected errors and the expected rates of error events, which together comprise a detector error model. Here we show that the syndrome history of QEC experiments is sufficient to correct coherent errors, removing the need for prior device benchmarking experiments. Importantly, our method shows that detector error models determined from syndromes work equally well for both stochastic and coherent noise regimes. We model fully-coherent or fully-stochastic noise for repetition and surface codes and for various phenomenological and circuit-level noise scenarios, by employing Majorana and Monte Carlo simulators. We additionally study several mixed stochastic-coherent noise models, and arbitrary single-qubit completely positive trace preserving maps. We capture the interference of coherent errors, which appears as enhanced or suppressed physical error rates compared to the stochastic case, and also observe hyperedges that do not appear in the corresponding Pauli-twirled models. Finally, we decode the detector error models undergoing coherent noise and find different thresholds compared to detector error models built based on the stochastic noise assumption.
