Emergence of multipartite optomechanical entanglement in microdisk cavities coupled to nanostring waveguide

In this paper, we propose a scheme to show signatures of multipartite optomechanical entanglement, which is based on two high quality factor (high- Q) silicon nitride (Si₃N₄) microdisk cavities coupled to a nanostring waveguide via evanescent field. Genuine tripartite optomechanical entanglement is shared in the subsystem even though the two fields of microdisk cavities do not have direct interaction. In addition, we study the behaviors of the bipartite entanglement between the pairs of the system constituents by numerical simulation.