基于相对熵的开放系统量子参数估计  

Quantum parameter estimation based on relative entropy in open systems

作　　者：杨志远 严凯[1,2] 邵雅婷 郝翔 YANG Zhiyuan;YAN Kai;SHAO Yating;HAO Xiang(School of Mathematics and Physics,SUST,Suzhou 215009,China;Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application,Suzhou 215009,China)

机构地区：[1]苏州科技大学数理学院,江苏苏州215009 [2]江苏省维纳热流技术与能源应用重点实验室,江苏苏州215009

出　　处：《苏州科技大学学报（自然科学版）》2020年第2期42-47,共6页Journal of Suzhou University of Science and Technology（Natural Science Edition）

基　　金：国家自然科学基金资助项目(61875145);苏州科技大学研究生创新工程项目(SKCX18_Y12)。

摘　　要：为了有效度量混合量子态的参数估计精度,利用量子相对熵,提出了一种量子信息散度,分析了量子信息散度与量子Fisher信息量的相互关联。以两能级量子系统为例,当量子系统经历三种典型的量子噪声通道时,分析了量子Fisher信息量和量子信息散度的含时演化规律。当被测参量变化相同数值时,量子信息散度比量子Fisher信息量衰减地更快。研究表明,量子信息散度的变化对环境噪声更加敏感,可以作为一种有效的量子测量方法。In order to effectively measure the parameter estimation precision of quantum mixed states,we put forward quantum information divergence based on relative entropy.The connection of quantum information divergence with quantum Fisher information was analyzed.For any qubit subjected to three typical quantum channels,the time evolution of both measures was studied.When the measured parameters vary with the same amount,the values of quantum information divergence decay more quickly than those of quantum Fisher information.The results show that quantum information divergence is more sensitive to the environmental noise and can be used as an effective method of quantum measurements.

关 键 词：量子相对熵 量子信息散度 量子Fisher信息 量子噪声通道 

分 类 号：O413.2[理学—理论物理]