Dissipation-induced optomechanical entanglement with the assistance of Coulomb interaction

We consider a hybrid three-mode optomechanical system where one mechanical oscillator couples to a second one via a Coulomb force and to a cavity mode via an optomechanical interaction. It is shown that stationary cavity-mechanical entanglement can be achieved by effectively cooling a Bogoliubov mode via the intermediate mode acting as an engineered reservoir. The entanglement can be maximized by carefully balancing the two confronting effects of the ratio of the effective couplings. Moreover, we analyze in detail the effects of the nonresonant terms. It is found that while the stability zone of the system shrinks in the parameter plane for large cooperativity, the maximal entanglement is not significantly reduced by the nonresonant terms. We numerically optimize the ratio in the stable region and obtain remarkably strong entanglement in the large cooperativity regime.