运动的二能级原子与单模双光子腔场的热纠缠现象  

Thermal Entanglement Between A Moving Two-Level Atom And A Single Mode Two-Photon Cavity

作　　者：王攀[1] 葛国勤[2] 

机构地区：[1]福建师范大学闽南科技学院,福建泉州362332 [2]华中科技大学物理学院,湖北武汉430074

出　　处：《延安大学学报（自然科学版）》2009年第2期52-56,共5页Journal of Yan'an University：Natural Science Edition

摘　　要：利用共生纠缠度(concurrence)研究了一个运动的二能级原子与一个双光子J-C模型相互作用,在热平衡态下,讨论了在旋波近似和非旋波近似下原子与腔场之间的纠缠随时间的演化。结果表明,需使原子与腔场形成纠缠,在旋波近似下,该系统有一个临界温度,并且该温度和腔场的结构以及原子的运动状态有关,如果耦合常数一定,原子与腔场的纠缠随着时间呈周期性变化,并且随着温度的升高,共生纠缠度C逐渐减小,如果原子的运动状态一定,则C随着耦合常数的增大而增大;在非旋波近似下,C随着耦合系数比的增大而增大,如果耦合系数比一定,则C也随着耦合常数的增大而增大,随着温度的增大而减小,和旋波近似有相似的性质。It investigates the interaction between a motion atom and a two -photon Jaynes -Cummings model by means of concurrence. It almost discusses the atom - cavity entanglement with the time evolution in the rotating wave approximation （RWA） and in the non - RWA, then a series of significant results have been obtained. In the RWA, it is shown that there exists a critical temperature if there exists entanglement between atom and cavity, and the temperature would have to do with the structure of the cavity and the motion state of the atom; if the coupling constant between the atom and the cavity keeps invariable, the atom - cavity entangled state appears with periodicity, which decrease with increasing temperature; if the motion state of atom keeps invariable, the concurrence increasing with the coupling constant. Then we analyzed the entanglement without the rotating wave approximation, the result showed that the concurrence increased with increasing the coupling coefficient ratio, if the coupling coefficient ratio keeped invariable, then the concurrence increased with increasing the coupling constant, and decreased with the increasing the temperature, which was familiar with the rotating wave approximation.

关 键 词：量子光学 JAYNES-CUMMINGS模型 热纠缠态 共生纠缠度 耦合常数 

分 类 号：O436[机械工程—光学工程]