Saved in:
Bibliographic Details
Main Authors: Xu, Tianyi, Liu, Qinglong, Wang, Maolin, Zhang, Fei, Zhao, Zhe, Wang, Yang, Wei, Ye
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.24640
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913065867411456
author Xu, Tianyi
Liu, Qinglong
Wang, Maolin
Zhang, Fei
Zhao, Zhe
Wang, Yang
Wei, Ye
author_facet Xu, Tianyi
Liu, Qinglong
Wang, Maolin
Zhang, Fei
Zhao, Zhe
Wang, Yang
Wei, Ye
contents Quantum computers could solve problems beyond the reach of classical devices, but this potential depends on quantum error correction (QEC) to protect fragile quantum states from noise. A central challenge in QEC is decoding: inferring likely physical errors from syndrome patterns generated by repeated stabilizer measurements. Existing decoders, including graph-based and neural approaches, typically return a single correction hypothesis and therefore discard the richer posterior structure of the error distribution conditioned on the observed syndrome. Here we recast QEC decoding as posterior inference using discrete denoising diffusion, exploiting the analogy between stochastic error accumulation and the forward diffusion process. We introduce DiffQEC, a generative decoder that combines a syndrome processor for multi-round spatial-temporal syndrome histories with syndrome feature modulation to condition denoising on the observed syndrome throughout inference. On experimental data from Google's superconducting quantum processor, DiffQEC reduces logical error rates by up to 10.2% relative to minimum-weight perfect matching and by about 5% relative to tensor-network decoding. These improvements persist for larger code distances up to 17 under depolarizing noise and for logical circuits of increasing depth. Beyond accuracy, the learned posterior provides confidence estimates for post-selection and reveals physically meaningful error structure, establishing posterior generative decoding as a practical framework for QEC.
format Preprint
id arxiv_https___arxiv_org_abs_2604_24640
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle DiffQEC: A versatile diffusion model for quantum error correction
Xu, Tianyi
Liu, Qinglong
Wang, Maolin
Zhang, Fei
Zhao, Zhe
Wang, Yang
Wei, Ye
Quantum Physics
Quantum computers could solve problems beyond the reach of classical devices, but this potential depends on quantum error correction (QEC) to protect fragile quantum states from noise. A central challenge in QEC is decoding: inferring likely physical errors from syndrome patterns generated by repeated stabilizer measurements. Existing decoders, including graph-based and neural approaches, typically return a single correction hypothesis and therefore discard the richer posterior structure of the error distribution conditioned on the observed syndrome. Here we recast QEC decoding as posterior inference using discrete denoising diffusion, exploiting the analogy between stochastic error accumulation and the forward diffusion process. We introduce DiffQEC, a generative decoder that combines a syndrome processor for multi-round spatial-temporal syndrome histories with syndrome feature modulation to condition denoising on the observed syndrome throughout inference. On experimental data from Google's superconducting quantum processor, DiffQEC reduces logical error rates by up to 10.2% relative to minimum-weight perfect matching and by about 5% relative to tensor-network decoding. These improvements persist for larger code distances up to 17 under depolarizing noise and for logical circuits of increasing depth. Beyond accuracy, the learned posterior provides confidence estimates for post-selection and reveals physically meaningful error structure, establishing posterior generative decoding as a practical framework for QEC.
title DiffQEC: A versatile diffusion model for quantum error correction
topic Quantum Physics
url https://arxiv.org/abs/2604.24640