相位退相干下二项式光场与原子相互作用的纠缠特性  

The Property of Entanglement of the Binomial Optical Field Interacting with the Atom Under Phase Decoherece Condition

作　　者：张冬霞[1,2] 萨楚尔夫[1,2] 牧其尔[1,2] 

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》2011年第2期105-112,共8页Journal of Quantum Optics

基　　金：国家自然科学基金(60467002);内蒙古自然科学基金(2009MS0112);内蒙古师大研究生科研基金(CXJJS10036)

摘　　要：利用全量子理论及部分转置矩阵负本征值的方法,研究了存在相位退相干时多光子T-C模型中两个二能级原子与二项式光场相互作用系统中两原子的纠缠演化特性。讨论了二项式光场的最大光子数M、二项式光场系数η、相位退相干系数γ、跃迁光子数m对原子间纠缠度的影响。结果表明:在γ的作用下,随着M的增加,两原子间纠缠较容易达到稳定的状态,且纠缠度的稳定值变大;选取适当的参量后,随着η的增加,两原子间的纠缠更容易趋于稳定状态,纠缠度稳定值将变小;η越小,纠缠演化的周期越明显。随着γ的增大,纠缠演化不具有周期性易趋于退纠缠。随着m的增大,振荡周期缩短,纠缠强度减弱。Abstract： By means of the quantum theory and the method of the negative eigenvalues of the partial transposition, the properties of entanglement evolution in the system of two two-level atoms coupled to a light field in the binomial state for radiation field are investigated in the presence of phase decoherence in themultiphoton Tavis-Cumming Model. The influences of the maximum number of photons, the coefficient of binomial state for radiation field, the phase decoherence coefficient and the number of the transitional photons on the entanglement degree between two atoms have been discussed. The results show that the entanglement between two atoms will get steady state more easily, and the steady value of the entanglement degree is bigger than before with the increase of the maximum number of photons in the presence of phase decoherence. The entanglement between two atoms will approach a steady state more easily. The steady value will be diminished with the increase of the coefficient of binomial state for radiation field in selecting the proper parameter. The periods of the entanglement evolution are more obvious when the coefficient ηof binomial state for radiation field is smaller. The entanglement evolution does not have the periodicity and tends the disentanglement phenomenon easily with the increase of the phase decoherence coefficient. The periods of the entanglement evolution is shorten and the entanglement intensity is weaken with the increase of the number of the transitional photons.

关 键 词：量子光学 二项式光场 部分转置矩阵负本征值 相位退相干因子 

分 类 号：O431[机械工程—光学工程]