基于超导电路量子电动力学系统的实时参数估计

实时量子参数估计是利用或发展统计估计方法来获取量子系统中未知参数的估计值，并提高参数估计的精度。它是量子反馈控制和自适应控制的基础。当前，量子参数估计已成为量子频标、弱磁场探测、引力波探测，以及原子钟等研究领域中的重要课题。本项目基于超导电路量子电动力学系统，实时估计该系统的相关参数(比如估计耗散系数以及噪声谱等)，并分析估计精度和估计性能极限，以及研究该系统中的量子最优测量和最优估计问题。为了获得更有效的测量输出，我们拟发展非对易算子同时测量方法，以此提高测量信号的信噪比。在估计方法上，我们借鉴粒子滤波方法，将贝叶斯滤波和蒙特卡罗采样应用到估计该量子系统的未知参数中。

Real-time quantum parameter estimation is to accurately estimate the value of an unknown parameter with the assistance of statistical methods. It is the basis of quantum feedback control and adaptive control. Now, it has become a fast developing discipline, which is closely related to practical applications, such as atomic clocks, quantum imaging, and gravitational wave detection, et al. Based on the superconducting circuit QED system, we propose the real-time quantum parameter estimation methods to estimate the dissipation rate and noise spectrum, and analyzes the estimation accuracy and the performance limit. Moreover, we study the optimal measurement and estimation problem in this area. We hope to develop the quantum simultaneous measurement of non-commuting observables method to enhance the SNR. Finally, we refer to the particle filter method and apply the Bayesian filter and Monte Carlo sampling methods to the estimation of unknown parameters in the circuit QED system.