Dynamics of quantum discord in a quantum critical environment
Dynamics of quantum discord in a quantum critical environment
复制标题
量子临界环境中量子不和谐的动力学
DOI：
10.1088/0953-4075/44/21/215501
复制
发表时间：
2011-11-14
影响因子：
1.6
通讯作者：
Li, Yongming
中科院分区：
文献类型：
--
作者：
Xi, Zhengjun;Lu, Xiao-Ming;Li, Yongming
我们研究了横向场中独立耦合到伊辛自旋链的两个量子位的量子不和谐（QD）动力学，该量子位表现出量子相变。对于该模型，我们驱动相应的Kraus算子，获得QD的解析结果，并将QD的动力学与临界点附近的纠缠相对熵的动力学进行比较。结果表明，量子临界环境对量子点的影响可以集中在临界点附近的一个非常狭窄的区域，因此为检测临界点提供了一种有效的方法。在临界点附近，量子点的演化比纠缠更复杂。此外，我们发现可分离态也可以用来反映环境的量子临界性。
We study the dynamics of quantum discord (QD) of two qubits independently coupled to an Ising spin chain in a transverse field, which exhibits a quantum phase transition. For this model, we drive the corresponding Kraus operators, obtain the analytic results of QD and compare the dynamics of QD with the dynamics of relative entropy of entanglement nearby the critical point. It is shown that the impact of the quantum criticality environment on QD can be concentrated in a very narrow region nearby the critical point, so it supplies an efficient way to detect the critical points. In the vicinity of the critical point, the evolution of QD is shown to be more complicated than that of entanglement. Furthermore, we find that separable states can also be used to reflect the quantum criticality of the environment.