Formation of the tripartite exciton-photon-vibron quasiparticle in a driven optomechanical system

We consider a coherently driven optomechanical system consisting of a cavity mode interacting with matter polarization that, in turn, excites vibrons-quanta of matter nuclei vibrations. We show that in this system, one can realize strong coupling between all three subsystems, resulting in the formation of the photon-exciton-vibron quasiparticle by transition through an exceptional point of the third order. We also demonstrate that by increasing the amplitude of the external drive, the system subsequently transits from strong coupling between photons and excitons through strong coupling between photons, excitons, and vibrons to strong coupling between photons and vibrons. The obtained results pave the way for controlling the type of strong coupling and excited quasiparticles.