Enhanced tripartite entanglement via atomic coherence in atom-optomechanical system

Abstract

We present a scheme to greatly enhance tripartite entanglement in an atom-optomechanical hybrid system driven by a single input laser field. The enhancement of the tripartite entanglement among two longitudinal cavity modes and a mirror oscillation mode is realized via atomic coherence when the cavity free spectral range is about equal to twice the frequency of mechanical oscillation and both cavity modes are blue-detuned by the mechanical frequency to the respective atomic resonant transitions while keeping the two-photon resonance satisfied. Moreover, the entanglement between the two cavity modes exhibits robustness to the variation of the environment temperature. The present atom-assisted optomechanical system provides an alternative platform for the quantum state exchange between light and light, as well as light and matter.