级联环境中两量子比特量子关联动力学研究  

The Dynamics of Quantum Correlation for Two Qubits in The Hierarchical Environment

作　　者：李亚鑫 李军奇[1] 梁九卿[1] LI Ya-xin;LI Jun-qi;LIANG Jiu-qing(Institute of Theoretical Physics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学理论物理研究所,山西太原030006

出　　处：《量子光学学报》2020年第2期105-113,共9页Journal of Quantum Optics

基　　金：国家自然科学基金(11105087,11404198);2017年山西省基础研究计划项目(201701D221001)。

摘　　要：本文研究了一个双量子比特系统中的量子纠缠和量子失协的动力学问题,在我们的模型中仅一个量子比特与级联环境相互作用。其中,级联环境由两层环境所组成,第一层环境为单个损失腔c0,而第二层环境是由存在耦合的N个损失腔所充当。结果表明:随着N和两层环境间耦合系数κ的增大,量子关联可得到有效提高。同时,量子比特与腔c0间的耦合系数Ω0,第二层环境的腔衰减率Γ和近邻腔模间的耦合系数Ω对量子关联也有着重要影响。另外,我们发现,量子失协和量子纠缠有类似的演化行为,但量子失协总小于或等于纠缠且比纠缠衰减地更快。The dynamics of quantum entanglement and quantum discord for a two-qubit system is explored in this paper,in which one qubit is isolated while the other is coupled with the hierarchical environment where one lossy cavity c0 plays as the first layer environment and the N-coupled lossy cavities as the second layer environment.It is shown that quantum correlation can be improved effectively with the increasing of the number of cavities N and the coupling strength κ between the two layers.In the meantime,the qubit-c0 coupling strength Ω0,the decay rate of cavities Γ and the coupling strength between two nearest-neighbor cavities Ω in the second-layer environment all have important influences on the quantum correlation.In addition,we find that the quantum discord has the similar time changes with entanglement,but which is always lesser than or equal to entanglement and has a faster decay than entanglement.

关 键 词：量子关联动力学 量子纠缠 量子失协 级联环境 

分 类 号：O431[机械工程—光学工程]