Enhancement of entanglement in distant mechanical vibrations via modulation in a coupled optomechanical system

We consider a coupled cavity optomechanical setup driven by a periodically modulated pump. We investigate the asymptotic behaviors of Heisenberg operator mean values and mechanical entanglement. It is shown that the system will acquire the same period of the modulation in the long time limit and, compared to the no modulation case, the mechanical entanglement can be significantly enhanced by periodic driving with more conservative system parameters and a higher permitted bath temperature. The mechanism of entanglement generation is discussed and an approximate optimal modulation frequency for small effective coupling is derived.