2023/06/29 by Laura Caune, Brendan N. Reid, Caune, Laura +5 · 5 citations
Computer Science · Mathematics · #Algorithm #Bandwidth (computing) #Belief propagation #Code (set theory) #Computation #Computer science #Decoding methods #FOS: Physical sciences #Matching (statistics) #Mathematics #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum-Dot Cellular Automata #Soft-decision decoder #Statistics #Telecommunications
paper · pdf · doi:10.48550/arxiv.2306.17142
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2023/06/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
One of the fundamental challenges in enabling fault-tolerant quantum computation is realising fast enough quantum decoders. We present a new two-stage decoder that accelerates the decoding cycle and boosts accuracy. In the first stage, a partial decoder based on belief propagation is used to correct errors that occurred with high probability. In the second stage, a conventional decoder corrects any remaining errors. We study the performance of our two-stage decoder with simulations using the surface code under circuit-level noise. When the conventional decoder is minimum-weight perfect matching, adding the partial decoder decreases bandwidth requirements, increases speed and improves logical accuracy. Specifically, we observe partial decoding consistently speeds up the minimum-weight perfect matching stage by between 2x-4x on average depending on the parameter regime, and raises the threshold from 0.94% to 1.02%.