标题： 量子比特失谐和串扰的最优校准 显示英文标题

标题： Optimal Calibration of Qubit Detuning and Crosstalk

摘要： 表征和校准物理量子位对于保持量子处理器的性能至关重要。 这一过程中的一个关键挑战是串扰的存在，这使得个体量子位失谐的估计变得复杂。 在本工作中，我们通过优化Ramsey干涉实验，利用Fisher信息和Cramer-Rao界，推导出估计失谐和串扰参数的最佳策略。 我们比较了几种校准协议，包括在多个时间点测量单个正交分量以及在单个时间点测量两个正交分量，在总测量次数固定的情况下。 我们的结果预测，后一种方法在孤立量子位和耦合量子位的情况下都能提供最高的精度和鲁棒性。 我们使用单个NV中心以及超导transmon量子位实验验证了我们的方法。 我们的方法能够在显著减少测量次数的情况下实现准确的参数提取，从而在保持估计精度的同时将校准时间减少多达50%。 显示英文摘要

摘要： Characterizing and calibrating physical qubits is essential for maintaining the performance of quantum processors. A key challenge in this process is the presence of crosstalk that complicates the estimation of individual qubit detunings. In this work, we derive optimal strategies for estimating detuning and crosstalk parameters by optimizing Ramsey interference experiments using Fisher information and the Cramer-Rao bound. We compare several calibration protocols, including measurements of a single quadrature at multiple times and of two quadratures at a single time, for a fixed number of total measurements. Our results predict that the latter approach yields the highest precision and robustness in both cases of isolated and coupled qubits. We validate experimentally our approach using a single NV center as well as superconducting transmons. Our approach enables accurate parameter extraction with significantly fewer measurements, resulting in up to a 50\% reduction in calibration time while maintaining estimation accuracy.