非线性Jaynes-Cummings模型中原子与光场的纠缠特性

Atom-field Entanglement Properties in Non-linear Jaynes-Cummings Model

利用密度矩阵的部分转置矩阵负本征值,研究了附加Kerr介质依赖强度耦合Jaynes-Cummings模型中原子与光场纠缠度随时间的演化特性,讨论了Kerr介质与不同初始光场对原子—光场纠缠度的影响.结果表明:原子—光场纠缠度随时间作周期性演化,其演化周期由光场与原子耦合强度以及光场与介质相互作用强度来确定,并随耦合强度和相互作用强度的增加而减小,其纠缠程度会随光场的初始状态的不同而产生明显的变化.

The atom-field entanglement properties in the intensity-dependent coupling JaynesCummings model with an additional Kerr medium are investigated by using negative eigenvalues of the partial transposition matrix of the density matrix. The influences of Kerr medium and initial field on atom-field entanglement degree are discussed. The results show that the time evolution of atomfield entanglement degree has the periodicity, for different preparations. The period depends on the strengthes of the field-atom coupling and field-medium interaction, with the increase of the strengthes, the period becomes smaller. The initial state of the field plays an important role in the atom-field entanglement degree.