物理学报2017，Vol.66Issue(20)：11-19,9.DOI:10.7498/aps.66.200301
基于量子相干性的四体贝尔不等式构建
Four-partite Bell inequalities based on quantum coherence
摘要
Abstract
It is well known that Bell inequalities are derived under the assumptions of locality and realism. Bell inequalities impose strict constraints on the statistical correlations of measurements of multipartite systems. Violating each of them guarantees the existence of quantum correlations in a quantum state. A quantum state with non-vanishing entanglement may violate some Bell inequalities. Recent progress of the fields like quantum biology and quantum thermodynamics reveals a particular role of quantum coherence in quantum information processing. Quantum coherence is identified by the presence of off-diagonal terms in the density matrix. To quantify quantum coherence of a given state, Baumgratz et al. (Baumgratz T, Cramer M, Plenio M B 2014 Phys. Rev. Lett. 113140401);provided several kinds of coherence measures such as l1-norm of coherence and relative entropy of coherence. In this paper, we propose to use quantum coherence to derive Bell inequalities. We construct the Bell inequalities of four-partite product states with l1-norm of coherence, relative entropy of coherence. In the Bell inequalities of four-partite correlations, measurement operators are products of local measurement operators. Each local operator is one of the two arbitrary observables. We consider the violations of the four-partite Bell inequalities by the four-partite general pure Greenberger-Horne-Zeilinger (GHZ) state, cluster states, W states with real coefficients. We also investigate the violations of the four-partite Bell inequalities by the four-partite GHZ class mixed states, cluster class mixed states, W class mixed states and Dicke class mixed states. It is shown that the four-partite Bell inequalities in terms of relative entropy of coherence are always violated by the four-partite general pure GHZ states, cluster states with the real coefficients. Hence there is non-vanishing entanglement for these states.关键词
贝尔不等式/量子相干性/多体量子态Key words
Bell inequalities/quantum coherence/multipartite quantum states引用本文复制引用
叶世强,陈小余..基于量子相干性的四体贝尔不等式构建[J].物理学报,2017,66(20):11-19,9.基金项目
国家自然科学基金(批准号: 11375152)资助的课题.Project support by the National Natural Science Foundation of China (Grant No. 11375152). （批准号: 11375152）
