Effective Hamiltonian of the Jaynes-Cummings model beyond rotating-wave approximation
Effective Hamiltonian of the Jaynes-Cummings model beyond rotating-wave approximation
复制标题
超越旋转波近似的 Jaynes-Cummings 模型的有效哈密顿量
DOI：
10.1088/1674-1056/abd930
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Sun Qing
中科院分区：
文献类型：
--
作者：
Wang Yifan;Yin Honghao;Yang Mingyue;Ji Anchun;Sun Qing
The Jaynes-Cummings model with or without rotating-wave approximation plays a major role to study the interaction between atom and light. We investigate the Jaynes-Cummings model beyond the rotating-wave approximation. Treating the counter-rotating terms as periodic drivings, we solve the model in the extended Floquet space. It is found that the full energy spectrum folded in the quasi-energy bands can be described by an effective Hamiltonian derived in the highfrequency regime. In contrast to the Z_2 symmetry of the original model, the effective Hamiltonian bears an enlarged U(1)symmetry with a unique photon-dependent atom-light detuning and coupling strength. We further analyze the energy spectrum, eigenstate fidelity and mean photon number of the resultant polaritons, which are shown to be in accordance with the numerical simulations in the extended Floquet space up to an ultra-strong coupling regime and are not altered significantly for a finite atom-light detuning. Our results suggest that the effective model provides a good starting point to investigate the rich physics brought by counter-rotating terms in the frame of Floquet theory.
