Actis: A Strictly Local Union-Find Decoder
Actis: A Strictly Local Union-Find Decoder
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DOI：
10.22331/q-2023-11-14-1183
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发表时间：
2023-05
期刊：
影响因子：
6.4
通讯作者：
Tim Chan;Simon C Benjamin
中科院分区：
文献类型：
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作者：
Tim Chan;Simon C Benjamin
容错量子计算需要经典硬件来执行纠错所需的解码。 Union–Find 解码器是最好的候选者之一。它具有显着的有机特征，涉及通过最近邻步骤进行数据结构的增长和合并；这自然表明了使用具有最近邻链接的简单处理器网格来实现它的可能性。通过这种方式，可以以近乎理想的并行性来分配计算负载。在这里，我们首次证明这种严格（而不是部分）局部性是实用的，最坏情况运行时间为 O(d3)，表面代码距离 d 的平均运行时间为二次方。采用了一种新颖的奇偶校验计算方案，可以简化之前提出的架构，并且我们的方法针对电路级噪声进行了优化。我们将本地实现与远程链接增强的实现进行比较；虽然后者当然更快，但我们注意到本地异步逻辑可以抵消差异。
Fault-tolerant quantum computing requires classical hardware to perform the decoding necessary for error correction. The Union–Find decoder is one of the best candidates for this. It has remarkably organic characteristics, involving the growth and merger of data structures through nearest-neighbour steps; this naturally suggests the possibility of its realisation using a lattice of simple processors with nearest-neighbour links. In this way the computational load can be distributed with near-ideal parallelism. Here we show for the first time that this strict (rather than partial) locality is practical, with a worst-case runtime O(d3) and mean runtime subquadratic in the surface code distance d. A novel parity-calculation scheme is employed which can simplify previously proposed architectures, and our approach is optimised for circuit-level noise. We compare our local realisation with one augmented by long-range links; while the latter is of course faster, we note that local asynchronous logic could negate the difference.