原子与光纤耦合腔相互作用系统中的纠缠特性

The Entanglement Properties in the System of Three Atoms Trapped in Two Distant Cavities Connected by An Optical Fiber

研究了光纤耦合腔A和B中各囚禁一个和两个二能级原子的情况,给出了总激发数为1时系统态矢的演化。采用Negativity熵来描述两个子系统间的纠缠,利用数值计算方法研究了腔内原子与原子间和腔场与腔场间的纠缠特性,讨论了光纤模与腔场间的耦合强度变化对纠缠特性的影响。另一方面还研究了对腔A中原子选择性测量对纠缠特性的影响。研究结果表明:随光纤模与腔场间的耦合系数增大,腔场间纠缠减弱。原子间纠缠与光纤模与腔场间的耦合系数间存在非线性关系。另一方面,采用原子态选择性测量方法,可增强腔内原子间和腔场间的纠缠。

Three two-level atoms are trapped in two initially empty cavities that are connected by an optical fiber.We investigate the entanglement evolution between two atoms in the same cavity and the entanglement evolution between two cavities.We discuss the influences of the state-selective measurement on the entanglement and that of fiber-cavity coupling coefficient on the entanglement.The obtained results show that atom-atom entanglement property has a nonlinear relation with increasing of the cavity-fiber coupling coefficient,and cavity-cavity entanglement property is weakened with increasing of the cavity-fiber coupling coefficient.On the other hand,the results also show that the entanglement between two cavities and that between two atoms can be strengthened through the state-selective measurement on the atom.