发表机构
Northwestern University; Fermi National Accelerator Laboratory; Amazon Center for Quantum Computing; Stanford University（西北大学; 费米国家加速器实验室; 亚马逊量子计算中心; 斯坦福大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对超导腔受非线性约瑟夫森元件频率波动导致的退相问题，提出Stark辅助磁通噪声规避（SAFE）协议，可大幅延长腔退相时间且残留驱动退相干占比低。
AI 中文摘要
高相干超导腔为量子信息提供了极具前景的平台，具有长相干时间和可忽略的本征退相特性。然而，腔控制通常依赖非线性约瑟夫森元件，其频率波动会作为退相被腔继承，可能限制控制保真度并削弱纠错协议中使用的噪声偏置。本文提出Stark辅助磁通噪声规避（SAFE）协议，这是一种硬件高效的方案，仅通过施加到非线性元件的弱失谐微波驱动即可保护腔免受继承的退相影响。作为具体装置，我们分析了受1/f磁通噪声影响的三维超导腔与磁通可调transmon（FTT）的色散耦合系统。分析预测通过具有实际参数的蒙特卡罗模拟得到验证，结果显示SAFE可将腔退相时间延长一个数量级以上，同时保持残留驱动诱导的退相干处于次要地位。
英文摘要
High-coherence superconducting cavities offer a promising platform for quantum information, with long coherence times and negligible intrinsic dephasing. However, cavity control generally relies on nonlinear Josephson elements whose frequency fluctuations are inherited by the cavity as dephasing, potentially limiting control fidelities and eroding the noise bias used in error-correction protocols. Here, we introduce Stark-Assisted Flux-noise Evasion (SAFE), a hardware-efficient protocol that protects the cavity from inherited dephasing using only a weak off-resonant microwave drive applied to the nonlinear element. As a concrete setup, we analyze a 3D superconducting cavity dispersively coupled to a flux-tunable transmon (FTT) subject to $1/f$ flux noise. Analytical predictions are confirmed by Monte Carlo simulations with realistic parameters, which show that SAFE can extend the cavity dephasing time by more than an order of magnitude while keeping residual drive-induced decoherence subdominant.
Comments24 pages, 8 figures
