Noise in quantum computing is countered with quantum error correction. Achieving optimal performance will require tailoring codes and decoding algorithms to account for features of realistic noise, such as the common situation where the noise is biased towards dephasing. Here we introduce an efficient high-threshold decoder for a noise-tailored surface code based on minimum-weight perfect matching. The decoder exploits the symmetries of its syndrome under the action of biased noise and generalizes to the fault-tolerant regime where measurements are unreliable. Using this decoder, we obtain fault-tolerant thresholds in excess of 6% for a phenomenological noise model in the limit where dephasing dominates. These gains persist even for modest noise biases: we find a threshold of ∼5% in an experimentally relevant regime where dephasing errors occur at a rate 100 times greater than bit-flip errors.

中文翻译：

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偏置噪声下，表面代码的容错阈值超过5％。

量子计算中的噪声可以通过量子误差校正来解决。要获得最佳性能，将需要定制代码和解码算法，以考虑实际噪声的特征，例如噪声偏于移相的常见情况。在这里，我们介绍了一种基于最小权重完美匹配的高效高阈值解码器，用于噪声定制的表面代码。解码器在偏置噪声的作用下利用其校验子的对称性，并推广到测量不可靠的容错机制。使用这种解码器，对于相移占主导的现象学现象噪声模型，我们获得了超过6％的容错阈值。这些增益即使对于适度的噪声偏置也仍然存在：