Room-temperature optomechanics with light-matter condensates

In this work, we develop an optomechanical formalism for macroscopic quantum states in exciton-polariton systems with strong exciton-phonon interactions. We show that polariton optomechanical interactions induce dynamical backaction, resulting in dispersive and dissipative shifts in the complex vibrational response functions. Unlike conventional optomechanical systems, polariton optomechanics features high-dimensionality and phase-space confinement due to the dispersion relations of exciton-polaritons. Consequently, vibrational modes exhibit effective positive or negative mass depending on the detuning parameter, and are capable for the nonequilibrium vibrational Bose-Einstein condensation under the resonant conditions [arXiv:2309.08498]. We demonstrate the potential for vibrational control of polariton condensates at room temperature.