损耗腔中场与原子的纠缠

Entanglement of Atom and Field in Lossy Cavity

讨论了系统预制在原子激发态和场真空态直积条件下,存在腔损耗的Jaynes-Cummings模型中场和原子的纠缠以及原子、光场和原子-场复合系统线性熵的时间演化。结果表明,在共振情况下,若腔损耗较小(κ<2g),退缠周期性地发生,若腔损耗较大(κ≥2g),退纠缠仅出现在初始时刻和稳态。失谐将减弱短时区纠缠而增强长时区纠缠。

Assuming that the atom-field system is prepared in the state of direct product by the excited state of the atom and the vacuum of the field. The time-evolution of entanglement and linear entropies of the atom, field and the atom field system in the Jaynes-Cummings model with the presence of cavity loss is investigated. Results show that in the resonant case,when the decay rate is small （k〈2g） ,the disentanglement of the system and returning to pure states of the subsystems will take place periodically. When the decay rate is large （k≥2g） ,the disentanglement occurs only at the beginning and in steady state. Detuning weakens the short-time period entanglement and strengthens the long-time period entanglement.