等距离光纤耦合腔系统中的三体纠缠特性

Tripartite Entanglement Dynamics in a Equidistance Cavities Coupled by Fibers

考虑3个单模腔处于等边三角形的3个顶点,腔与腔之间通过光纤耦合,并且每个腔囚禁一个二能级原子的情况,研究了该系统中3个原子间和3个腔模间的三体纠缠特性.考虑系统激发数等于1的情况下,给出了系统态矢的演化规律;采用三体负本征值Negativity度量三体纠缠,通过数值计算给出了3个原子间和3个腔模间的三体纠缠演化曲线;讨论了腔模与光纤模间的耦合强度变化对纠缠特性的影响.研究结果表明:原子间和腔模间的三体纠缠量均呈现不规则振荡;随着腔模与光纤模间耦合系数增大,振荡频率增大,而原子间和腔模间的三体纠缠均减弱.

When the three separated equidistance single-mode cavities were positioned at the three vertices of an equilateral triangle,the characteristic of the tripartite entanglement among the cavities and that among atoms in the system was studied.The situation was considered which three identical two-level atoms are separately trapped in cavities.Each atom resonantly interacts with cavity via a one-photon hopping.The evolution of the state vector of the system was given when the total excitation number of the system equals one.Negativity was adopted to quantify the degree of tripartite entanglement among three subsystems.The tripartite entanglement dynamics among atoms and that among cavities were studied.The influences of cavity-fiber coupling constant on the tripartite entanglement among atoms and that among cavities were discussed.The results obtained using the numerical method show that,the tripartite entanglement among atoms and that among cavities are weakened with increase of cavity-fiber coupling coefficient.