报告题目：Mean photon number dependent variational method to the Rabi model

报告人：刘卯鑫博士  北京邮电大学物理系

报告时间：2018年11月2日（星期三） 下午14:00-15:00

报告地点：物理科技楼113

报告邀请人：尤文龙

报告摘要：

Abstract: We present a mean-photon-number dependent variational method, which works well in whole coupling regime if the photon energy is dominant over the spin-flipping, to evaluate the properties of the Rabi model for both the ground state and the excited states. For the ground state, it is shown that the previous approximate methods, the generalized rotating-wave approximation (only working well in the strong coupling limit) and the generalized variational method (only working well in the weak coupling limit), can be recovered in the corresponding coupling limits. The key point of our method is to tailor the merits of these two existing methods by introducing a mean-photon-number dependent variational parameter. For the excited states,our method yields considerable improvements over the generalized rotating-wave approximation. The variational method proposed could be readily applied to the more complex models, for which an analytic formula is difficult to be formulated.