标题： 用于超导量子器件的电离辐射消除 显示英文标题

标题： Abatement of Ionizing Radiation for Superconducting Quantum Devices

摘要： 电离辐射已被证明会降低超导量子电路的性能。 在这份报告中，我们评估了典型超导量子比特实验平台中不同环境放射性来源的预期贡献。 我们对典型低温恒温器内部放射性的评估突显了选择适当材料的重要性，这些材料用于靠近量子比特设备的实验组件，例如封装和电气互连。 我们提出了一种浅层地下设施（相当于30米水深）以减少宇宙射线通量，并使用铅屏蔽的低温恒温器来减轻实验室环境中自然发生的放射性伽马射线通量。 我们预测，在这个设施中运行的超导量子比特设备可能会经历相关多量子比特错误率的降低，这一降低幅度大约是典型地上、未屏蔽设施中的1/20。 最后，我们概述了为了进一步降低残余电离辐射率所需的总体设计改进，达到当前直接探测暗物质实验的极限。 显示英文摘要

摘要： Ionizing radiation has been shown to reduce the performance of superconducting quantum circuits. In this report, we evaluate the expected contributions of different sources of ambient radioactivity for typical superconducting qubit experiment platforms. Our assessment of radioactivity inside a typical cryostat highlights the importance of selecting appropriate materials for the experiment components nearest to qubit devices, such as packaging and electrical interconnects. We present a shallow underground facility (30-meter water equivalent) to reduce the flux of cosmic rays and a lead shielded cryostat to abate the naturally occurring radiogenic gamma-ray flux in the laboratory environment. We predict that superconducting qubit devices operated in this facility could experience a reduced rate of correlated multi-qubit errors by a factor of approximately 20 relative to the rate in a typical above-ground, unshielded facility. Finally, we outline overall design improvements that would be required to further reduce the residual ionizing radiation rate, down to the limit of current generation direct detection dark matter experiments.