双光子Jaynes-Cummings模型中的纠缠演化和热纠缠态现象

文中利用共生纠缠度研究了双光子Jaynes-Cummings模型中原子与腔纠缠的时间演化和有限温度下系统热纠缠态.结果表明,腔场中原子与腔展现出周期性的纠缠演化过程,演化周期随原子与腔耦合强度的增大而减小;在有限温度下,系统的共生纠缠度随温度的升高而降低,当趋近临界温度时,系统纠缠现象消失,这一临界温度值与原子-腔耦合强度成正比.对于典型的实验数据,临界温度大约在～10-5 K数量级.

Entanglement and thermal entanglement in two-photon Jaynes-Cummings model

We investigate atom-cavity entanglement in the time evolution and the thermal entanglement in two-photon Jaynes-Cummings model by means of concurrence. The result shows that atom-cavity entangled state appears with periodicity, which decreases with the increasing coupling strength between the atom and cavity; In finite temperature, the concurrence decreases with the increasing of temperature, thermal entanglement vanishes in this Jaynes-Cummings model when system temperature reaches the critical temperature, which is proportional to the coupling strength of atom-cavity. For typical experimental data, the critical temperature is on the order of 10~(-5) K.