Chen Zhihua, Ye Xiangjun, Fei Shao-Ming
Department of Mathematics, College of Science, Zhejiang University of Technology, Hangzhou, 310023, China.
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, China.
Sci Rep. 2017 Nov 17;7(1):15822. doi: 10.1038/s41598-017-15910-8.
Occupying a position between entanglement and Bell nonlocality, Einstein-Podolsky-Rosen (EPR) steering has attracted increasing attention in recent years. Many criteria have been proposed and experimentally implemented to characterize EPR-steering. Nevertheless, only a few results are available to quantify steerability using analytical results. In this work, we propose a method for quantifying the steerability in two-qubit quantum states in the two-setting EPR-steering scenario, using the connection between joint measurability and steerability. We derive an analytical formula for the steerability of a class of X-states. The sufficient and necessary conditions for two-setting EPR-steering are presented. Based on these results, a class of asymmetric states, namely, one-way steerable states, are obtained.
处于纠缠与贝尔非定域性之间的爱因斯坦 - 波多尔斯基 - 罗森（EPR）引导近年来受到了越来越多的关注。已经提出并通过实验实现了许多准则来表征EPR引导。然而，利用解析结果来量化引导性的结果却很少。在这项工作中，我们利用联合可测量性与引导性之间的联系，提出了一种在双设置EPR引导场景中量化两比特量子态引导性的方法。我们推导了一类X态引导性的解析公式。给出了双设置EPR引导的充分必要条件。基于这些结果，得到了一类非对称态，即单向可引导态。
