多光子跃迁下二能级原子与NPS态光场相互作用系统的纠缠特性

Entanglement characteristics in system of two-level atom of multi-photon transition interacting with NPS light field

利用全量子理论研究了NPS态光场与二能级原子相互作用系统的纠缠特性。计算了系统纠缠度表达式,分析了原子初态、光场相位参数、最大光子数、光场参数和跃迁光子数对系统纠缠特性的影响。结果表明:原子初态处在叠加态且光场相位参数较小时,系统的纠缠度较大;选取合适的最大光子数和跃迁光子数时,光场参数越小,系统纠缠现象越明显。

Entanglement characteristics in a system of a two-level atom interacting with a number-phase state （NPS） field are investigated by using the fully quantum theory. The entanglement degree expression of the system is calculated. Influences of the initial atomic state, parameters of field phase, largest-photon number, parameters of light field and transition photon number on the system entanglement degree are analyzed. Results show that when the initial atomic state is in superposition state, and the field phase parameter is small relatively, the system entanglement degree is large relatively. When the appropriate largest-photon numbers and transitional photon numbers are chosen, the smaller the field parameter is, the more obvious the entanglement phenomenon will be.