Bell态原子与双模纠缠相干光场双光子相互作用系统的量子纠缠

Entanglement in the System of Atoms in Bell States Interacting with the Two-mode Entangled Coherent Field Via Two-photon Process

运用全量子理论和数值计算的方法,借助于原子的量子约化熵研究了初始处于Bell态|β00>和|β10>的两原子与双模纠缠相干光场双光子相互作用系统中两原子与双模光场之间纠缠的演化特性。分析了光场强度、光场纠缠度及原子间相互作用强度对原子熵演化特性的影响。结果表明:随着双模光场的平均光子数的增大,原子熵的时间演化曲线逐渐变为规则振荡;增大原子间的相互作用强度,原子熵的振荡频率和振幅都减小;改变双模光场的纠缠度,原子熵的振荡频率和振幅都不发生改变。

The entanglement time evolution of atoms in Bell states ｜β300 〉 and ｜β10 〉 interacting with the two- mode entangled coherent field is investigated by means of full quantum theory and numerical calculations. The effects of the atoms＇ initial state, mean photon numbers of field, the degree of the entanglement for the entangled coherent fields, and thee coupling strength of interaction between atoms on the entanglement are discussed. The results show that the entropy time evolutions appear regular with the increase of the mean photon numbers of field. The frequency and amplitude of the oscillation decrease with the increase of the coupling strength of interaction between atoms. But when the degree of the entanglement for the entangled coherent fields changes, the frequency and amplitude of the entropy oscillation won＇t change.