考虑初始处于纠缠态的两原子,分别以一定的速率依次通过高Q粒子数场,利用negativity度量纠缠的方法,研究了两原子之间的纠缠演化与原子初态和光场状态的关系,并与两原子同时在腔场时的情况做了比较。发现:当粒子数场为真空场时,两种模型下双原子纠缠度均做周期性演化;当粒子数场为非真空场时,双原子纠缠度都会出现纠缠猝死现象。并进一步研究了该现象随初始纠缠参量θ、粒子数n的变化关系以及与环境(腔场)的纠缠转移问题。

By using the negativity method,we study the entanglement dynamics of two entangled atoms,which are in two levels,that go through the high Q fields in the Fock state one by one.The results shows that the initial state of the two-atom and the field in the Fock state are influenced by the entanglement dynamics of two atoms,and we also make the significant comparison of the two-atom entanglement evolutions in the condition that the two atoms are laid in the QED at the same time.We find that:when the cavity field is in the vacuum state,the two-atom entanglements under these two models evolve periodicity; when we choose the cavity field in a Fock state,the entanglement between the two atoms can appear tobe the phenomenon of entanglement sudden death.Furthermore,we investigate the entanglement transfer problem and the relationship among entanglement sudden death,the initial state,and the number of the Fock state.