Dynamical Casimir effect in a hybrid cavity optomechanical system

In this paper, we show that the dynamical Casimir effect can be observed in a hybrid cavity optomechanical system. By introducing a two-level atom into the cavity, the atomic transition from an excited state to the ground state can evoke a two-photon process. Our proposal does not require a driving field to induce the dynamical Casimir effect, which is very alternative to previous schemes. Furthermore, we show that when the atom is replaced by an identical atomic ensemble, the system not only can simulate the similar dynamic Casimir effect, but also exist more plentiful physical phenomena, i.e., higher-order resonance. Numerical simulation confirms the validity of our derivation.