论文标题
局部预码，以减少量子误差校正的带宽和延迟
A local pre-decoder to reduce the bandwidth and latency of quantum error correction
论文作者
论文摘要
经典解码系统与量子硬件接口以执行量子误差校正，将支持容忍故障的量子计算机。在物理体系结构施加的通信限制内，解码器必须与量子时钟速度保持同步。为此，我们提出了一个本地的“预码”，这使贪婪的校正以减少发送到标准匹配解码器的综合征数据的数量。我们研究了具有不完美测量值的现象学相叉噪声模型，研究表面代码的这些经典开销。我们发现，通过使用前编码器，我们发现全局解码器的运行时和通信带宽方面有很大改进。例如，为了实现$ f = 10^{ - 15} $的逻辑故障概率，使用带有物理错误率的Qubits $ p = 10^{ - 3} $和A距离$ d = 22 $代码，我们发现频段的成本降低了$ 1000 $，并且由匹配的解码器所花费的时间是$ 200 $ $ $ $ $ 200 $。为了达到此目标故障概率，与最佳解码器相比，预码方法需要增加量子计数$ 50 \％$。
A fault-tolerant quantum computer will be supported by a classical decoding system interfacing with quantum hardware to perform quantum error correction. It is important that the decoder can keep pace with the quantum clock speed, within the limitations on communication that are imposed by the physical architecture. To this end we propose a local `pre-decoder', which makes greedy corrections to reduce the amount of syndrome data sent to a standard matching decoder. We study these classical overheads for the surface code under a phenomenological phase-flip noise model with imperfect measurements. We find substantial improvements in the runtime of the global decoder and the communication bandwidth by using the pre-decoder. For instance, to achieve a logical failure probability of $f = 10^{-15}$ using qubits with physical error rate $p = 10^{-3}$ and a distance $d=22$ code, we find that the bandwidth cost is reduced by a factor of $1000$, and the time taken by a matching decoder is sped up by a factor of $200$. To achieve this target failure probability, the pre-decoding approach requires a $50\%$ increase in the qubit count compared with the optimal decoder.
