论文

神经分流解码框架将高码率 qLDPC 码解码延迟降低一到两个数量级

Fast and accurate neural triage decoding of ultra-high-rate quantum LDPC codes

精选理由

量子纠错圈的实用进展:Triage 解码器准确率媲美最优算法解码器,延迟还快一到两个数量级,做容错量子计算的可以看看。

论文提出 neural triage decoding(神经分流解码)框架,利用综合征一致性自适应分配神经计算资源,包含局部神经消息传递网络、迭代修正和极少触发的多样化搜索三个阶段。Triage 解码器可解码编码数百个逻辑量子比特的超高码率 qLDPC 码,包括 lifted-product 和 Kasai 码。在准确率接近最优算法解码器的同时,解码延迟降低约一到两个数量级。研究还基于对精确逐比特边缘解码器的严格分析,揭示了与码距无关的综合征不一致错误平台,并证明神经网络解码器对错误先验失配具有鲁棒性。

原文 · arXiv cs.LG

Fast and accurate neural triage decoding of ultra-high-rate quantum LDPC codes

Quantum error correction is essential for fault-tolerant quantum computing. High-rate quantum low-density parity-check (qLDPC) codes have emerged as a promising approach to reducing the substantial physical qubit overhead of quantum error correction, enabling encoding rates exceeding $1/2$ in blocks of approximately one thousand physical data qubits. However, their practical implementation requires decoders that combine high accuracy with low latency to keep pace with quantum hardware. Existing decoders of high-rate qLDPC codes can achieve high accuracy but often incur substantial computational latency, whereas neural network decoders have yet to be demonstrated for high-rate qLDPC codes. Here, we introduce \emph{neural triage decoding}, a framework that uses syndrome consistency to adaptively allocate neural computation. A local neural message-passing network rapidly predicts error corrections, additional iterations reduce residual syndrome violations, and a rarely invoked diversification stage searches for consistent corrections to the remaining shots. We demonstrate that the \texttt{Triage} decoder can decode ultra-high-rate qLDPC codes encoding a few hundred logical qubits, including lifted-product and Kasai codes, achieving state-of-the-art accuracy comparable to the near optimal algorithmic decoders while reducing decoding latency by approximately one to two orders of magnitude. Our framework is inspired by a rigorous analysis of the exact bitwise marginal decoder, revealing a distance-independent syndrome-inconsistent error floor. In addition, we show the robustness of neural network decoders to mismatched error priors. Our results establish adaptive neural decoding as a promising route towards fast, accurate, and scalable quantum error correction in the near term.