GPU-Accelerated Syndrome Decoding for Quantum LDPC Codes below the 63 $μ$s Latency Threshold

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ferraz, Oscar, Coutinho, Bruno, Falcao, Gabriel, Gomes, Marco, Monteiro, Francisco A., Silva, Vitor
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916891134525440
author Ferraz, Oscar
Coutinho, Bruno
Falcao, Gabriel
Gomes, Marco
Monteiro, Francisco A.
Silva, Vitor
author_facet Ferraz, Oscar
Coutinho, Bruno
Falcao, Gabriel
Gomes, Marco
Monteiro, Francisco A.
Silva, Vitor
contents This paper presents a GPU-accelerated decoder for quantum low-density parity-check (QLDPC) codes that achieves sub-$63$ $μ$s latency, below the surface code decoder's real-time threshold demonstrated on Google's Willow quantum processor. While surface codes have demonstrated below-threshold performance, the encoding rates approach zero as code distances increase, posing challenges for scalability. Recently proposed QLDPC codes, such as those by Panteleev and Kalachev, offer constant-rate encoding and asymptotic goodness but introduce higher decoding complexity. To address such limitation, this work presents a parallelized belief propagation decoder leveraging syndrome information on commodity GPU hardware. Parallelism was exploited to maximize performance within the limits of target latency, allowing decoding latencies under $50$ $μ$s for [[$784$, $24$, $24$]] codes and as low as $23.3$ $μ$s for smaller codes, meeting the tight timing constraints of superconducting qubit cycles. These results show that real-time, scalable decoding of asymptotically good quantum codes is achievable using widely available commodity hardware, advancing the feasibility of fault-tolerant quantum computation beyond surface codes.
format Preprint
id arxiv_https___arxiv_org_abs_2508_07879
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle GPU-Accelerated Syndrome Decoding for Quantum LDPC Codes below the 63 $μ$s Latency Threshold
Ferraz, Oscar
Coutinho, Bruno
Falcao, Gabriel
Gomes, Marco
Monteiro, Francisco A.
Silva, Vitor
Quantum Physics
Distributed, Parallel, and Cluster Computing
This paper presents a GPU-accelerated decoder for quantum low-density parity-check (QLDPC) codes that achieves sub-$63$ $μ$s latency, below the surface code decoder's real-time threshold demonstrated on Google's Willow quantum processor. While surface codes have demonstrated below-threshold performance, the encoding rates approach zero as code distances increase, posing challenges for scalability. Recently proposed QLDPC codes, such as those by Panteleev and Kalachev, offer constant-rate encoding and asymptotic goodness but introduce higher decoding complexity. To address such limitation, this work presents a parallelized belief propagation decoder leveraging syndrome information on commodity GPU hardware. Parallelism was exploited to maximize performance within the limits of target latency, allowing decoding latencies under $50$ $μ$s for [[$784$, $24$, $24$]] codes and as low as $23.3$ $μ$s for smaller codes, meeting the tight timing constraints of superconducting qubit cycles. These results show that real-time, scalable decoding of asymptotically good quantum codes is achievable using widely available commodity hardware, advancing the feasibility of fault-tolerant quantum computation beyond surface codes.
title GPU-Accelerated Syndrome Decoding for Quantum LDPC Codes below the 63 $μ$s Latency Threshold
topic Quantum Physics
Distributed, Parallel, and Cluster Computing
url https://arxiv.org/abs/2508.07879