Optomechanical entanglement induced by backward stimulated Brillouin scattering

We propose a scheme to generate robust optomechanical entanglement, i.e., the entanglement between a mechanical and an optical modes. This scheme is based on a Backward Stimulated Brillouin Scattering (BSBS) process, which is hosted within an optomechanical structure. Our benchmark system consists of an acoustic (mechanical) mode coupled to two optical modes through an electrostrictive (radiation pressure) effect. After determining the optimal acoustic parameters allowing the entanglement in our system, we have shown that both the acoustic coupling and the decay rate require a certain threshold from where the optomechanical entanglement is generated. For instance, to generate an optomechanical entanglement in our proposal, the strength of the used acoustic decay rate most exceed both the mechanical and optical decay rates, which is the figure of merit of our proposal. The generated entanglement is robust enough against thermal fluctuation. Our work provides a new scheme for entanglement generation based on BSBS effect, and can be extended to microwaves and hybrid optomechanical structures. Such a generated entangled states can be used for quantum information processing, quantum sensing, and quantum computing. •The generated entanglement depends on acoustic parameters from specific threshold.•The generated entanglement is greatly enhanced for at least up to one order of magnitude.•The generated entanglement survives for thermal phonon occupancy up to nth=200.