经典激光场驱动下的两量子比特纠缠动力学

利用超算符的方法研究了在经典激光场驱动下，分别囚禁在两个独立腔中的两个二能级原子的纠缠动力学。结果表明：两原子纠缠与腔场相干态的初始值无关，并且在腔场耗散比较小的时候，经典光驱动场会加速两原子的纠缠突然死亡，但是在腔场耗散比较大的时候，经典驱动场可以保护原子纠缠免于突然死亡。这说明即便在“坏”腔中，我们也可以通过加经典驱动场来避免原子纠缠突然死亡。

Entanglement dynamics of two qubits driven by classical laser field

The entanglement dynamics of two two-level atoms which are respectively trapped in two independent dissipative single-mode cavities and strongly driven by the classical fields is investigated analytically utilizing the super operator method.It is found that the entanglement is not related to the initial value of the cavity coherent states.The driving field enhances the entanglement sudden death for small dissipation of the cavity,while it protects the entanglement from sudden death for large dissipation in the presence of strong driving field.These results show that even in the bad cavity (with large decay rate),the entanglement can be free from sudden death with the assistance of classical driving field.