基于一个二比特自旋模型的量子失协动力学研究  

Dynamics of Quantum Discord based on a Two-qubit Spin Model

作　　者：任珊珊 杨国晖[1] REN Shan-shan;YANG Guo-hui(School of Physics and Information Engineering,Shanxi Normal University,Linfen 041000,Shanxi,China)

机构地区：[1]山西师范大学物理与信息工程学院,山西临汾041000

出　　处：《山西师范大学学报（自然科学版）》2018年第4期42-47,共6页Journal of Shanxi Normal University(Natural Science Edition)

摘　　要：研究了在DM相互作用下,非均匀磁场中的二比特自旋模型的量子失协动力学,即其随时间的演化问题,分析DM相互作用D、非均匀磁场的不均匀度b、初态的纯度r等参量对量子失协和量子纠缠的影响.通过研究发现,在D、b、r三个参量改变时,QD和C在很大程度上有着相似的行为,两者都以波动形式变化,但QD和C也有着明显的不同,即QD不会发生突然消失的现象,但量子纠缠却会突然消失.因此,在许多领域内,量子失协是比纠缠更普遍的存在,拥有更大的应用价值,通过改变各个参量的值,我们可以更好的控制其随时间的演化.Dynamics of quantum discord of the two-qubit spin model in a non-uniform magnetic field under the DM interaction is investigated. And the effects of the parameters the DM interaction D,the inhomogeneity of the non-uniform magnetic field b and the purity r of the initial state to the quantum discord and the quantum entanglement are investigated. It is found that when the three parameters of D,σ and r are changed,QD and C have similar behavior to a large extent. Both of them change in the form of fluctuation,but there is a distinct difference between QD and C,that is,QD does not suddenly disappear,but the quantum entanglement will suddenly disappear. Therefore,in many fields,quantum discord is a more common existence than quantum entanglement,and has greater application value. By changing the values of each parameter,we can better control the evolution of quantum discord with time.

关 键 词：量子失协 纠缠 ISING模型 

分 类 号：O459[理学—无线电物理]