两二能级原子在共同环境下的量子关联动力学  

Quantum correlation dynamics of two two-level atoms in common environment

作　　者：贺志[1] 李龙武[2] 

机构地区：[1]湖南文理学院物理与电子科学学院,常德415000 [2]北京理工大学物理学院,北京100081

出　　处：《物理学报》2013年第18期27-33,共7页Acta Physica Sinica

基　　金：国家自然科学基金专项基金(批准号:11247294);湖南省教育厅一般项目(批准号:12C0826);湖南文理学院博士启动基金(批准号:13101039)资助的课题~~

摘　　要：通过精确求解带有偶极-偶极相互作用的两个二能级原子与一个共同热库相互作用模型,得到了两原子间量子纠缠和量子失谐(quantum discord)的解析表达式.综合考虑了环境的非马尔可夫效应、原子间的偶极-偶极相互作用以及原子的本征频率同腔模中心频率之间的失谐量对两原子间量子纠缠和quantum discord的影响.研究显示:在非马尔可夫机制下,且原子的本征频率与腔模中心频率是共振时,当两原子初态处于纠缠态时,原子间偶极-偶极相互作用可以显著抑制包括量子纠缠和quantum discord等量子关联的衰减,更特别的是,如果原子的本征频率同腔模中心频率有一定的失谐时,利用原子间偶极-偶极相互作用可大大地延长两原子退纠缠的时间;当两原子初态处于可分离态时,从短时间来看,原子间偶极-偶极相互作用可以提高量子纠缠和quantum discord振荡的振幅,而在长时间极限下,原子间偶极-偶极相互作用不会改变量子纠缠和quantum discord达到的稳定值.最后,讨论了原子间偶极-偶极相互作用对量子纠缠和quantum discord动力学不同的影响.By exactly solving the model of two two-level atoms with dipole-dipole interaction, interacting with a common environment, quantum entanglement and quantum discord of two atoms are obtained. In this paper, the influences of the non-Markovian effect of environment, the dipole-dipole interaction of two atoms and the detunings of the central frequency of the cavity and the transition frequency of the atoms on quantum entanglement and quantum discord dynamics of two atoms are comprehensively considered. The study shows that in the non-Markovian regime and the resonant case, if two atoms are initially in the entangled state, the damping of quantum entanglement and quantum discord will be remarkably suppressed. More specially, in the off-resonant case, the disentan- glement time of the two atoms can be considerably prolonged. On the other hand, if two atoms are initially in the separable state, the dipole-dipole interaction can enhance the amplitude of oscillations of quantum entanglement and quantum discord in a short time, but the steady values of quantum entanglement and quantum discord cannot be changed by the dipole-dipole interaction in the long- time limit. Finally, the different influences of the dipole-dipole interaction on quantum entanglement and quantum discord also are discussed.

关 键 词：量子纠缠 量子失谐 共同环境 偶极-偶极相互作用 

分 类 号：O431.2[机械工程—光学工程]