Ground-state cooling of the mechanical oscillator in a two-cavity optomechanical system

Abstract

In this paper, we theoretically study the ground-state cooling of the mechanical oscillator by an electromagnetically-induced transparency (EIT)-like cooling mechanism in a two-cavity optomechanical system, with a quarter-wave plate placed inside, which plays a linear coupling role in the two cavities. Based on the perturbation theory and quantum Langevin equation, we derive the rate equation of the mechanical oscillator and the fluctuation spectrum of the effective optical force. We find that the maximum value of optical fluctuation spectrum corresponds to the cooling process of the mechanical oscillator, and the minimum value of optical fluctuation spectrum corresponds to the heating process of the mechanical oscillator. With the help of the quarter-wave plate, the heating process can be greatly suppressed due to the quantum interference effect. The ground-state cooling of the mechanical oscillator via such an EIT-like cooling mechanism can be implemented beyond the resolved sideband regime.