研究了初始处于GHZ态的三个两能级原子与双模腔场相互作用系统的纠缠动力学特性,得到了并发度和线性熵的解析表达式。讨论了腔场初始纠缠度对腔内两原子之间纠缠的影响,对其余子系统求迹后结果表明腔内两原子之间的纠缠出现突然产生现象,腔内两原子之间产生纠缠的阈值时间和最大值依赖于双模腔场初始纠缠度;并且发现腔内两原子子系统和腔外原子与场子系统之间在整个的时间演化过程中一直保持着纠缠状态。

The dynamics of entanglement of three two-level atoms initially in GHZ state system interacting with a bimodal cavity field are investigated in this paper and the analytical expressions of the concurrence and linear entropy are obtained. The effect of the initial entanglement of the cavity field is analyzed on the time evolution of the entanglement between two atoms inside the cavity. It is shown that the phenomenon of sudden birth of entanglement between two atoms trapped in a cavity occurs by tracing out the other subsystems. The threshold time and the maximum for the creation of the entanglement are dependent on the initial entanglement of the cavity field. The two atoms inside the cavity subsystem and the subsystem of the atom outside the cavity and the field are entangled in the overall time evolution process.