多光子Tavis-Cummings模型中两纠缠原子的纠缠演化特性

研究了两个纠缠的二能级原子通过多光子跃迁与单模相干光场进行耦合相互作用系统中两原子纠缠的演化特性.计算分析表明，两个原子之间的纠缠呈现出周期性的演化特性，初始两原子的状态、原子间的偶极相互作用、相干光场的参数以及跃迁光子数对两个原子的纠缠有着显著的影响；并发现两原子初始处于某最大纠缠态时，两原子会永远处于该最大纠缠态，因此这一类最大纠缠态可以作为一种量子信息存储器. 关键词： 量子纠缠 部分转置矩阵负本征值 纠缠原子 相干态

The entanglement character of two entangled atoms in multiphoton Tavis-Cummings model

We investigated the entanglement time evolution of two entangled two-level atoms. The two atoms can undergo muhiphoton transition when they interact resonantly with a single-mode field in the coherent state. The results show that the two-atom entangled state evolves periodicity. The influence of the two-atom initial state, the dipole-dipole coupling intensity between two atoms, the parameter of the coherent state and the number of the transitional photons on the entanglement degree of two atoms are revealed. When the initial state is a maximum entangled state, the state of the two entangled atoms will forever stay in this maximum entangled state. So this kind of entanglement state can be used for quantum information storage.