相位退相干对T-C模型中两纠缠原子纠缠度的影响  

Influence of the phase decoherence on the entanglement of two entangled atoms in T-C model

作　　者：单传家[1] 程维文[1] 刘堂昆[1] 黄燕霞[1] 李宏[1] 夏云杰[2] 

机构地区：[1]湖北师范学院物理系,湖北黄石435002 [2]曲阜师范大学物理工程学院,山东曲阜273165

出　　处：《光电子．激光》2008年第2期270-274,共5页Journal of Optoelectronics·Laser

基　　金：湖北省教育厅科学技术研究重大资助项目(X200522001);湖北省科技厅科学技术研究重点资助项目(2006ABA055);湖北师范学院研究生启动项目(2007D20)

摘　　要：采用全量子理论方法,研究了存在相位退相干的2个纠缠的两能级原子与真空场进行相互作用系统中两原子的纠缠演化。结果表明:相位退相干系数、初始两原子的状态和原子间的偶极相互作用对腔中2个原子的纠缠有着显著的影响。研究发现:考虑存在相位退相干时,两原子纠缠是一逐渐衰减的波动过程,最后趋于稳定的值,这个稳定值与开始两原子的状态和偶级相互作用有关;即使存在相位退相干,如果适当选择原子的初态,两原子会永远处于最大纠缠态。By means of the quantum theory,we investigate the system of two two-level atoms coupled to a single mode cavity in the vacuum state with the phase decoherence and calculate the entanglement time evolution between two atoms in the presence of phase decoherence. It is shown that the influences of the phase decoherence coeffident, the two-atom initial state and the dipole- dipole coupling intensity between two atoms on the entanglement degree of two atoms are revealed. The phase decoherence causes the fading of entanglement between two atoms,the entanglement will quickly become a constant with the increasing of the phase deeoherence coefficient; the constant value is affected by the two-atom initial state and the dipole- dipole coupling intensity. Meanwhile the two-atom quantum state will forever stay in the maximum entangled state when the initial state is proper even in the presence of phase decoherence.

关 键 词：相位退相干 量子纠缠 偶极相互作用 部分转置矩阵 

分 类 号：O431[机械工程—光学工程]