两个耦合二能级原子与单模热场作用系统中的量子和经典关联  

The Quantum Correlations and Classical Correlation in a System of Two Coupled Two-level Atoms Interacting with a Single Mode Thermal Field

作　　者：朱冬梅 萨楚尔夫[1,2] 苏少龙[1] ZHU Dong-mei;Sachuerfu;SU Shao-long(College of Physics and Electronic Information,Inner Mongolia Normal University,Hohhot 010022,China;Library,Inner Mongolia Normal University,Hohhot 010022,China)

机构地区：[1]内蒙古师范大学物理与电子信息学院,内蒙古呼和浩特010022 [2]内蒙古师范大学图书馆,内蒙古呼和浩特010022

出　　处：《量子光学学报》2021年第4期271-281,共11页Journal of Quantum Optics

基　　金：内蒙古自然科学基金(2019MS03024);内蒙古师范大学“十百千”人才基金(RCPY-2-2012-K-038)。

摘　　要：运用量子纠缠、量子关联与经典关联的概念及全量子理论方法,在一定条件下,研究了两个耦合二能级原子与热场相互作用系统中量子纠缠、量子失协、几何量子失协和经典关联的演化特性。分析和讨论了初始时刻两原子处于分离态时,原子与热辐射场耦合强度、热场平均光子数对系统中两原子间量子纠缠、量子关联和经典关联演化特性的影响。结果表明:在原子与热场耦合作用较弱时,随热场平均光子数的增大,两原子间的量子纠缠、量子关联的演化呈现突然死亡和再生现象,在长时域上表现为幅值逐渐减小的塌缩-复原过程,经典关联的演化表现为稳定的振荡形式;在原子与热场耦合作用较强时,随热场平均光子数的增大,量子纠缠、量子关联的变化仍会呈现突然死亡和再生现象,在长时域上四个量都表现为无规振荡形式,取值均明显减小,且发现在量子纠缠为零的时域上,明确存在着其他量子关联现象。Using the concepts of quantum entanglement,quantum correlations and classical correlation and the method of full quantum theory,the evolution properties of quantum entanglement,quantum discord,geometrical quantum discord and classical correlation in a system of two coupled two-level atoms interacting with a single mode electromagnetic field in a thermal state are studied under the certain conditions.When the two atoms are in the separated state at the initial time,we analyze the effects of the coupling strength between the two coupled two-level atoms and a single mode radiation field in a thermal state.At the same time,we also discuss the mean photon number on the evolution properties of quantum entanglement,quantum correlations and classical correlation between the two atoms in the system.The results show that when an atom weakly coupled to thermal field,the evolution of quantum entanglement,quantum discord and geometrical quantum discord between two coupled two-level atoms present the phenomenon of sudden death and sudden birth with the increase of the mean photon number of a single mode radiation field in a thermal state,which exhibit a collapse-revival process with gradually decreasing amplitude in the long time scale,and the evolution of classical correlation shows a stable oscillation form.When the effective coupling constant between the atom and a single mode electromagnetic field in a thermal state is stronger,the changes of quantum entanglement and quantum correlations still show the phenomenon of sudden death and sudden birth with increase of the mean photon number of a single mode radiation field in a thermal state.The four quantities are all in the form of irregular oscillation and the values of them significantly reduce in the long time scale.It is found that the other quantum corrections remain in the absence of quantum entanglement in the observed period of time.

关 键 词：单模热场 量子纠缠 量子失谐 几何量子失谐 经典关联 

分 类 号：O431.2[机械工程—光学工程]