摘要
We investigate the continuous variable entanglement in a four-level atom according to the criterion proposed by Duan et al.[Phys.Rev.Lett.84(2000)2722].The atomic coherence is introduced using two external classical driving fields.We study the steady-state entanglement of the system in the presence of losses,concluding that the creation of entangled states can be achievable under certain conditions.
基金
the National Natural Science Foundation of China under Grant No 11247311
the Innovation Program of Shanghai Municipal Education Commission under Grant No 11YZ216
the Excellent Young Scientist of Shanghai Municipal Education Commission under Grant No shgc js018
the Natural Science Foundation of Shanghai under Grant No 11ZR1414500.
