Entangling optical and mechanical cavity modes in an optomechanical crystal nanobeam

A scheme for the generation of steady-state entanglement between optical and mechanical cavity modes in an optomechanical crystal nanobeam is proposed. Based on finite element simulation and the quantum Langevin equation, we explore the evolution of entanglement with optomechanical properties in various device configurations, and demonstrate the ability of optimal entanglement generation in both blue and red detuned optical pumps. The intrinsic relationship between optomechanical cooperativity and entanglement is further clarified for depicting a clear physical picture of optomechanical interaction. Our work expands the understanding of macroscopic quantum mechanics and is an important step for developing novel quantum optomechanical devices.