Journal of the Optical Society of America B
Scheme for enhancing quadripartite entangled optical modes from an opto-mechanical system
Jing Zhang, Xiaoyu Liu, Rongguo Yang, Tiancai Zhang
Abstract
Multipartite entanglement is a key resource for quantum information processing and quantum communication. We show that the robust entanglement among four filtered output optical modes can be achieved when there is a nonlinear crystal inside an optomechanical cavity. The optical parametric amplifier (OPA) gives rise to single-mode squeezing of the cavity modes; therefore, the entanglement among four output optical modes can be enhanced remarkably. Furthermore, the degree of quadripartite entanglement is influenced by the nonlinear gain of OPA and bandwidth of the filters. Large entanglement can be obtained by optimizing the filter functions, which is important for utilizing entangled light beams more efficiently in real experiments. This kind of multipartite entanglement will be useful and valuable in the area of quantum communication networks.