Generalized rotating-wave approximation for the quantum Rabi model with optomechanical interaction
Abstract
We investigate the spectrum of energy and eigenstates of a hybrid cavity optomechanical system, where a cavity field mode interacts with a mechanical mode of a vibrating end mirror via radiation pressure and with a two level atom via electric dipole interaction. In the spirit of approximations developed for the quantum Rabi model beyond rotating-wave approximation (RWA), we implement the so-called generalized RWA (GRWA) to diagonalize the tripartite Hamiltonian for arbitrary large couplings. Notably, the GRWA approach still allows to rewrite the hybrid Hamiltonian in a bipartite form, like a Rabi model with dressed atom-field states (polaritons) coupled to mechanical modes through reparametrized coupling strenght and Rabi frequency. We found a more accurate energy spectrum for a wide range of values of the atom-photon and photon-phonon couplings, when compared to the RWA results. The fidelity between the numerical eigenstates and its approximated counterparts is also calculated. The degree of polariton-phonon entanglement of the eigenstates presents a non-monotonic behavior as the atom-photon coupling varies, in contrast to the characteristic monotonic increase in the RWA treatment.
Cite
@article{arxiv.2303.16164,
title = {Generalized rotating-wave approximation for the quantum Rabi model with optomechanical interaction},
author = {Wallace H. Montaño and Jesús A. Maytorena},
journal= {arXiv preprint arXiv:2303.16164},
year = {2023}
}