Efficient ground state cooling of a membrane by the combination of continuous-wave field and pulses

Abstract

We present an approach that realizes the ground state cooling of the membrane-in-middle optomechanical system. Instead of straightforwardly using the continuous-wave (CW) or pulsed external drives, we consider the combinations of them for having a more efficient cooling process. Due to the dynamical nature of the joint action of both CW and pulse fields, it is necessary to explore the real-time evolutions of the system under various conditions, from which the optimal cooling can be found. Given such setup, the cooling limit previously discovered for the simple optomechanical systems under a single CW drive can be easily broken. The achieved cooling effect indicated by a defined cooling rate is one or more order lower than the cooling limit of a simple optomechanical systems, thus providing an efficient way of ground state cooling. Furthermore, the ground state cooling can be realized for a membrane with much lower mechanical quality factor and with the external drives of the lower intensities, to considerably relax the requirements for optomechanical cooling with the current experimental technology.