标题： 宇宙射线和超导量子比特阵列中相关误差的同步检测 显示英文标题

标题： Synchronous Detection of Cosmic Rays and Correlated Errors in Superconducting Qubit Arrays

摘要： 规模化的量子信息处理将需要足够稳定且寿命足够长的量子比特，这可能由纠错码实现。 然而，最近几项超导量子比特实验报告称观察到了间歇性的时空相关错误，这对传统编码是有问题的，电离辐射可能是主要原因。 在此，我们直接测量了宇宙射线对时空相关量子比特错误的贡献。 我们通过同步监测宇宙射线探测器和分布在5x5x0.35 mm$^3$硅芯片上的10个transmon量子比特的能量弛豫动力学来完成这一测量。 宇宙射线以每10分钟1次的速率导致相关错误，占所有此类事件的17$\pm$1%。 我们的量子比特对基本上所有入射到芯片上的宇宙射线及其次级粒子都有响应，这与独立测量的到达通量一致。 此外，我们观察到，靠近约瑟夫森结的超导能隙的分布显著影响量子比特对宇宙射线的响应。 鉴于屏蔽宇宙射线的实际困难，我们的结果表明，辐射加固（例如，超导能隙工程）对于实现稳健的量子纠错至关重要。 显示英文摘要

摘要： Quantum information processing at scale will require sufficiently stable and long-lived qubits, likely enabled by error-correction codes. Several recent superconducting-qubit experiments, however, reported observing intermittent spatiotemporally correlated errors that would be problematic for conventional codes, with ionizing radiation being a likely cause. Here, we directly measured the cosmic-ray contribution to spatiotemporally correlated qubit errors. We accomplished this by synchronously monitoring cosmic-ray detectors and qubit energy-relaxation dynamics of 10 transmon qubits distributed across a 5x5x0.35 mm$^3$ silicon chip. Cosmic rays caused correlated errors at a rate of 1/(10 min), accounting for 17$\pm$1% of all such events. Our qubits responded to essentially all of the cosmic rays and their secondary particles incident on the chip, consistent with the independently measured arrival flux. Moreover, we observed that the landscape of the superconducting gap in proximity to the Josephson junctions dramatically impacts the qubit response to cosmic rays. Given the practical difficulties associated with shielding cosmic rays, our results indicate the importance of radiation hardening -- for example, superconducting gap engineering -- to the realization of robust quantum error correction.