各向异性和自旋耦合参数对海森堡XYZ链量子纠缠的影响  

Influences of Anisotropy and Spin Coupling Parameters on Quantum Entanglement of Heisenberg XYZ Chain

作　　者：慕琦雄 杨晶 罗丹丹[1] 单传家 彭新华 黄燕霞 Mu Qixiong;Yang Jing;Luo Dandan;Shan Chuanjia;Peng Xinhua;Huang Yanxia(College of Physics and Electronic Science,Hubei Normal University,Huangshi,Hubei 435002,China;Key Laboratory of Quantum Information,Chinese Academy of Sciences,Hefei,Anhui 230026,China;Department of Modern Physics,University of Science and Technology of China,Hefei,Anhui 230026,China)

机构地区：[1]湖北师范大学物理与电子科学学院,湖北黄石435002 [2]中国科学院量子信息重点实验室,安徽合肥230026 [3]中国科学技术大学近代物理系,安徽合肥230026

出　　处：《激光与光电子学进展》2019年第24期219-225,共7页Laser & Optoelectronics Progress

基　　金：湖北师范大学研究生创新科研基金项目（2018035）

摘　　要：利用concurrence作为纠缠度量,研究了z方向非均匀磁场中双量子比特的海森堡XYZ模型及其基态纠缠在不同参数范围内的性质,通过计算得出了临界磁场值,讨论了平均磁场和临界磁场与量子相变的关系,分析了两个相邻量子位自旋z分量Jz的相互作用和各向异性参数γB、γJ对海森堡模型热纠缠的影响,通过绘制图像说明了各向异性、自旋耦合参数Jz和热纠缠之间的关系。研究结果表明:在双量子比特系统中,对于有效的温度T,当耦合参数Jz=0时,随着γJ的增加,临界磁场Bc减小,纠缠逐渐消失;但是当耦合参数Jz>0时,对各向异性参数γB、γJ取合适的值,随着Jz的增加,纠缠度达到最大值的磁场范围和温度范围都变大,且纠缠得到有效增强。Herein,we study the Heisenberg two-qubit XYZchain in a z-directional non-uniform magnetic field by considering concurrence to be the entanglement metric.Further,we explore the properties of ground-state entanglement in different parameter ranges,calculate the critical magnetic field value,and discuss the relations between the average/critical magnetic fields and the quantum phase transition.We also analyze the interaction of the two adjacent qubits of the z-component Jzof the spin and investigate the influences of the anisotropy parametersγB andγJ on the thermal entanglement of the Heisenberg model.The relations among the anisotropy,coupling parameter Jz,and thermal entanglement can be better illustrated by drawing images.The results denote that in a two-qubit system at an effective temperature T,the critical magnetic field Bcdecreases and the entanglement gradually disappears asγJincreases when the coupling parameter Jzis equal to 0.However,when the coupling parameter Jz is greater than 0,the ranges of magnetic field and temperature with the maximum degree of entanglement increase with increasing Jzfor appropriate values of the anisotropy parametersγBandγJ,effectively enhancing the entanglement.

关 键 词：量子光学 海森堡模型 热纠缠 各向异性 自旋耦合参数 

分 类 号：O431.2[机械工程—光学工程]