Bell态原子与双模纠缠相干光场相互作用的纠缠特性

Entropy properties in the system of atoms in Bell states interacting with the two-mode entangled coherent field

运用Negativity熵研究了Bell态原子与双模纠缠相干光场相互作用系统中两个全同二能级原子之间的纠缠演化特性.分析了光场强度、光场纠缠度及原子间相互作用强度对纠缠的影响.结果表明:原子处于|β11〉时,两原子始终处于最大纠缠态;原子处于|β00〉时,初始纠缠的两原子始终较长时间处于退纠缠状态;原子处在|β10〉时,增大双模光场的平均光子数可以明显增大两原子之间的纠缠度并保持较大的纠缠状态;原子初态处在|β01〉时,原子间的相互作用强度对双原子间纠缠度有较显著的非线性调制作用.

The entanglement time evolution of atoms in Bell states interacting with the two-mode entangled coherent field is investigated by means of Negativity. The effects of the atoms initial state,mean photon numbers of field, the degree of the entanglement for the entangled coherent fields, and the coupling strength of interaction between atoms on the Negativity are discussed. The results shows that the two-atom entanglement state will forever stay in the maximum entangled state when the initial state is ｜β11）, while the Bell state ｜β00） atoms appear disentanglement most of the time. For the state ｜β10） mean photon numbers of field can be a great help, and in the state ｜β01 ） the coupling strength of interaction between atoms plays a major role in the two-atom entanglement.