Dithered Belief Propagation for Real-Time Quantum Memory Decoding
Abstract
We introduce dithered belief-propagation decoding for circuit-level quantum memory to mitigate the oscillations and trapping behavior that limit standard belief-propagation (BP) decoders for qLDPC codes. Our approach combines a quantum-adapted sign-flip mechanism with chained randomized prior perturbation. Evaluated under circuit-level noise on the distance-11 rotated surface code and the distance-12 bivariate-bicycle code, the proposed dithered decoder significantly outperforms BP and BP+OSD+CS-10. The proposed decoder achieves accuracy comparable to or better than state-of-the-art Relay-BP, especially at higher physical error rates, while trading a moderate increase in additions for about 98% fewer multiplications on average and eliminating node-level RNGs. These results suggest that dithering is a promising approach toward real-time decoding of quantum memories.
Related
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BibTeX
@misc{cai2026dithered,
title = {{Dithered Belief Propagation for Real-Time Quantum Memory Decoding}},
author = {Zhengyu Cai and Mohamad Ali Jarkas and Bokun Zhao and Warren J. Gross},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.07144},
eprint = {2611.07144},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.07144},
}
RIS
TY - UNPB
TI - Dithered Belief Propagation for Real-Time Quantum Memory Decoding
AU - Zhengyu Cai
AU - Mohamad Ali Jarkas
AU - Bokun Zhao
AU - Warren J. Gross
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.07144
UR - https://arxiv.org/abs/2611.07144
AB - We introduce dithered belief-propagation decoding for circuit-level quantum memory to mitigate the oscillations and trapping behavior that limit standard belief-propagation (BP) decoders for qLDPC codes. Our approach combines a quantum-adapted sign-flip mechanism with chained randomized prior perturbation. Evaluated under circuit-level noise on the distance-11 rotated surface code and the distance-12 bivariate-bicycle code, the proposed dithered decoder significantly outperforms BP and BP+OSD+CS-10. The proposed decoder achieves accuracy comparable to or better than state-of-the-art Relay-BP, especially at higher physical error rates, while trading a moderate increase in additions for about 98% fewer multiplications on average and eliminating node-level RNGs. These results suggest that dithering is a promising approach toward real-time decoding of quantum memories.
ER -