arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1709.02154quant-ph
收藏

二维拓扑码的多径求和译码

Multi-path Summation for Decoding 2D Topological Codes

Ben Criger, Imran Ashraf

摘要:

容错是可扩展量子计算的前提。基于2D拓扑码的体系结构对于容错的近期实现是有效的。为了获得高性能与这些架构,我们需要一个解码器,它可以适应各种各样的错误模型在实验中。解码表面码的问题的典型方法是以提供次优阈值错误率的方式将其减少到最小权重完美匹配,并且专门用于校正特定错误模型。最近,各种误差模型的最佳阈值误差率已经通过不使用最小权重完美匹配的方法获得,表明这种阈值可以在多项式时间内实现。这是一个悬而未决的问题,这些结果是否也可以通过最小权重完美匹配来实现。在这项工作中,我们使用的信念传播和一种新的算法产生的边缘权重,以增加效用的最小重量完美匹配解码表面码。这允许我们使用旋转表面码来校正去极化误差,从而获得$17.76 \pm 0.02 \%$的阈值。这大于由先前的基于匹配的解码器($14.88 \pm 0.02 \%$)实现的阈值,但仍低于$\sim 18.9 \%$的已知上限。

英文摘要:

Fault tolerance is a prerequisite for scalable quantum computing. Architectures based on 2D topological codes are effective for near-term implementations of fault tolerance. To obtain high performance with these architectures, we require a decoder which can adapt to the wide variety of error models present in experiments. The typical approach to the problem of decoding the surface code is to reduce it to minimum-weight perfect matching in a way that provides a suboptimal threshold error rate, and is specialized to correct a specific error model. Recently, optimal threshold error rates for a variety of error models have been obtained by methods which do not use minimum-weight perfect matching, showing that such thresholds can be achieved in polynomial time. It is an open question whether these results can also be achieved by minimum-weight perfect matching. In this work, we use belief propagation and a novel algorithm for producing edge weights to increase the utility of minimum-weight perfect matching for decoding surface codes. This allows us to correct depolarizing errors using the rotated surface code, obtaining a threshold of $17.76 \pm 0.02 \%$. This is larger than the threshold achieved by previous matching-based decoders ($14.88 \pm 0.02 \%$), though still below the known upper bound of $\sim 18.9 \%$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑