Multi-field-driven optomechanical entanglement.

Cavity optomechanical (COM) entanglement, playing an essential role in building quantum networks and enhancing quantum sensors, is usually weak and easily destroyed by noises. As feasible and effective ways to overcome this obstacle, optical or mechanical parametric modulations have been used to improve the quality of quantum squeezing or entanglement in various COM systems. However, the possibility of combining these powerful means to enhance COM entanglement has yet to be explored. Here, we fill this gap by studying a COM system containing an intra-cavity optical parametric amplifier (OPA), driven optically and mechanically. By tuning the relative strength and the frequency mismatch of optical and mechanical driving fields, we find that constructive interference can emerge and significantly improve the strength of COM entanglement and its robustness to thermal noises. This work sheds what we believe to be a new light on preparing and protecting quantum states with multi-field driven COM systems for diverse applications.