Hybrid Quantum Optomechanics with Graphene Nanoresonators

We report on the realization of a hybrid quantum system consisting of a graphene nanoresonator coupled to an ultracold spin ensemble. This work is motivated by the large quantum nonlinearities inherent to graphene resonators, as well as the strong atom-resonator coupling due to their commensurate mass ratio. We fabricate micromechanical suspended graphene membrane resonators and study their properties, both through spectroscopic and interferometric imaging. With dark field images, we relate the nonlinear intermode coupling in graphene to the quality factors of the modes. This work provides a foundation for the studies of entanglement between a macroscopic graphene membrane and an auxiliary quantum system of ultracold atoms. Additionally, such graphene resonators can be used for force, position, and mass sensing in the quantum limit.