具有三体相互作用自旋链的量子相干与量子纠缠  

Quantum Coherence and Quantum Entanglement in the Spin Chain with Three-site Interaction

作　　者：杨晶 黄燕霞 YANG Jing;HUANG Yan-xia(Faculty of Education,Guangdong Baiyun University,Guangzhou 510450,China;College of Physics and Electronic Science,Hubei Normal University,Huangshi 435002,China;Key Laboratory of Quantum Information,University of Science and Technology of China,Chinese Academy of Science,Hefei 230026,China)

机构地区：[1]广东白云学院教育学院,广东广州510450 [2]湖北师范大学物理与电子科学学院,湖北黄石435002 [3]中国科学院量子信息重点实验室,安徽合肥230026

出　　处：《量子光学学报》2023年第1期32-41,共10页Journal of Quantum Optics

基　　金：中国科学院量子信息重点实验室开放课题(KQI201);广东省普通高校青年创新人才项目(2021KQNCX118);广东白云学院校级科研项目(2022BYKY02)。

摘　　要：本文研究了具有两种三体相互作用的海森堡XXZ自旋链的量子相干与量子纠缠的特性。研究发现,量子相干性不会出现突然死亡现象且非零量子相干性存在的温度范围大于量子纠缠存在的温度范围,说明量子相干性相对于量子纠缠,具有更强的鲁棒性。在量子临界环境中,量子相干性可以表征本模型的量子相变现象。在铁磁情形中,无论外磁场是否为0,单独调控XZX+YZY三体相互作用对于减缓量子相干性的衰减速率与增大量子相干性存在的温度范围效果最好。在反铁磁情形中,外磁场为0时,XZX+YZY与XZY-YZX两种三体相互作用的协同作用可以显著增加量子相干性的最大值,并明显减缓其衰减速率。在铁磁情形与反铁磁情形中都发现当外磁场B<0时,量子相干性存在的温度范围更大,更有利于保存量子相干性。In this paper,quantum entanglement and quantum coherence in the XxZ Heisenberg spin chain with three-site interaction are investigated.We employ concurrence and relative entropy to measure quantum entanglement and quantum coherence.The influence of XZX+YZY three-site interaction,XZY-YZX three-site interaction,and magnetic field on the concurrence and the relative entropy vary with temperature are mainly studied.It is found that there is no sudden death phenomena in quantum coherence,and the temperature range of quantum coherence is larger than that of quantum entanglement.In addition,at absolute zero temperature,quantum coherence can characterize the quantum phase transition phenomena.In the ferromagnetic case,increasing XZX+YZY three-site interaction is the most effective way to reduce the attenuation rate and enlarge the temperature range of quantum coherence.Nevertheless,in the anti-ferromagnetic case,the cooperation effect of XZX+YZY and XZY-YZX three-site interaction can increase the maximum quantum coherence significantly and retard its decay rate at zero magnetic field.Additionally,in ferromagnetic and anti-ferromagnetic cases,when magnetic field B<O,the temperature range of quantum coherence is increased obviously,which is beneficial to preserve nonzero quantum coherence.

关 键 词：量子光学 三体相互作用 量子相干 量子纠缠 

分 类 号：O431.2[机械工程—光学工程]