文献类型：期刊文献

英文题名：Optimal Estimation of Quantum Coherence by Bell State Measurement: A Case Study

作者：Yuan, Yuan[1];Huang, Xufeng[1];Niu, Yueping[1,2,3];Gong, Shangqing[1,2,3]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]Shanghai Engn Res Ctr Hierarch Nanomat, Shanghai 200237, Peoples R China;[3]Shanghai Frontiers Sci Ctr Optogenet Tech Cell Met, Shanghai 200237, Peoples R China

年份：2023

卷号：25

期号：10

外文期刊名：ENTROPY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001093568200001)】；

基金：Yuan Yuan thanks Zhibo Hou for helpful discussions.

语种：英文

外文关键词：quantum coherence; Bell state measurement; maximum likelihood estimation; quantum measurement

摘要：Quantum coherence is the most distinguished feature of quantum mechanics. As an important resource, it is widely applied to quantum information technologies, including quantum algorithms, quantum computation, quantum key distribution, and quantum metrology, so it is important to develop tools for efficient estimation of the coherence. Bell state measurement plays an important role in quantum information processing. In particular, it can also, as a two-copy collective measurement, directly measure the quantum coherence of an unknown quantum state in the experiment, and does not need any optimization procedures, feedback, or complex mathematical calculations. In this paper, we analyze the performance of estimating quantum coherence with Bell state measurement for a qubit case from the perspective of semiparametric estimation and single-parameter estimation. The numerical results show that Bell state measurement is the optimal measurement for estimating several frequently-used coherence quantifiers, and it has been demonstrated in the perspective of the quantum limit of semiparametric estimation and Fisher information.