多光子Tavis-Cummings模型中运动原子与二项式光场相互作用的量子纠缠

Quantum entanglement of binomial field interacting with moving atoms in multiphoton Tavis-Cummings model

利用全量子理论,研究了多光子Tavis-Cummings模型中运动原子与二项式光场相互作用系统的量子纠缠特性,讨论了不同初始状态下的二项式光场系数和原子运动速度对纠缠特性的影响。结果表明:二项式光场系数不影响场熵演化的周期性,但影响场熵峰值大小。随着原子跃迁光子数的增多,场熵演化的周期性和消纠缠现象逐渐消失。原子运动的速度影响场熵的演化周期,且影响场熵峰值的大小,而原子跃迁光子数的增大,会消弱原子运动速度对场熵演化的影响。当光场处于中间态,原子运动速度较低,且原子跃迁光子数较大时,光场与原子可以长久地处于量子纠缠态。

The field entropy evolution of two moving atoms interacting with the binomial field in the multiphoton Tavis-Cumming model is studied. Influences of the atomic motion and parameters of the binomial light field on the field entropy are discussed by means of full quantum theory. The results indicate that parameters of the binomial optical field do not influence periodicity of evolution of the field entropy, but it has effect on the value of the filed entropy. With increase of photon number of atomic transition, the periodicity of evolution of the field entropy and the disentanglement were disappearing gradually. The speed of moving atoms affects the periodicity of evolution of field entropy and the value of entropy. But the increase of photon number of atomic transition will weaken the influence of atomic motion on the field entropy. When the field is in the middle states, the speed of atoms is lower and the photon number of atomic transition is larger, the binomial field and the two atoms will be in entangled state for a long time.