多光子跃迁下Rabi模型的量子相变

Quantum Phase Transition in Rabi Model under Multiple-Photon Transition

Rabi模型一直是近年来研究的热点,本文研究该模型在多光子跃迁下的量子相变及多稳态。通过自旋相干态变分法等效的赝自旋哈密顿量被对角化并解得了系统的能量泛函表达式,同时根据变分结果求得光子数解的情形和临界值,最后给出基于光子数解和系统稳定性相图。本文主要给出了单光子、两光子和多光子跃迁对Rabi模型量子态、多稳性和量子相变的影响。该结果有助于实验上通过调控腔频来诱导有趣的量子相变。

Rabi model has been a hot topic in recent years.In this paper,quantum phase transitions and multistable states in Rabi model are presented under multiple-photon transition.By means of spin-coherent-state variational method,the equivalent pseudospin Hamiltonian is diagonalized and the energy functional is obtained.Then according to the results of the variational method,the photon number solutions and the critical values are given.Finally,phase diagrams are plotted based on the photon number solutions and the stabilities.The main results are what effects do the numbers of transitions photons have on quantum states,multistability and quantum phase transitions in Rabi model.The results are helpful to induce interesting quantum phase transition by modulating the frequency of the optical cavity.