标题： 两个量子比特态在噪声环境中的非局域关联退化 显示英文标题

标题： Dilapidation of nonlocal correlations of two qubit states in noisy environment

摘要： 复合量子系统表现出非局域关联。 这些反直觉的关联是量子信息处理和量子计算的资源。 在我们之前对两个量子比特最大纠缠混合态的研究中，我们观察到，可以用于量子隐形传态的纠缠态、违反Bell-CHSH不等式的态以及不承认局部隐变量描述的态，在非局域关联的顺序上存在层次结构。 为了建立这一层次结构，在本工作中，我们研究了噪声对表现出更高阶非局域关联的两个量子比特态的影响。 我们发现，在噪声存在的情况下，非局域关联的退化遵循相同的层次结构，即高阶非局域关联在噪声强度较小时消失，而低阶非局域关联则能在强噪声环境中存活。 我们展示了由于振幅阻尼信道导致退相干的各种量子态的结果。 然而，我们观察到，由于相位阻尼以及去极化信道导致退相干的态也遵循相同的层次结构。 显示英文摘要

摘要： Composite quantum systems exhibit non-local correlations. These counter intuitive correlations form a resource for quantum information processing and quantum computation. In our previous work on two qubit maximally entangled mixed states, we observed that entangled states, states that can be used for quantum teleportaion, states that violate Bell-CHSH inequality and states that do not admit local hidden variable description is the hierarchy in terms of the order of nonlocal correlations. In order to establish this hierarchy, in the present work, we investigate the effect of noise on two quibt states that exhibit higher order nonlocal correlations. We find that dilapidation of nonlocal correlations in the presence of noise follow the same hierarchy, that is, higher order nonlocal correlation disappears for small strength of noise, where as lower order nonlocal correlations survive strong noisy environment. We show the results for decoherence due to amplitude damping channel on various quantum states. However, we observe that same hierarchy is followed by states undergoing decoherence due to phase damping as well as depolarizing channels.