Coupling mechanical motion of a single atom to a micromechanical cantilever

Abstract

We design and analyze a hybrid optomechanical setup to achieve an effective coupling between the mechanical motions of a micromechanical cantilever and a single atom trapped inside a cavity, which is mediated by a direct interaction between the micromechanical cantilever and the atomic internal state via the quantum vacuum effect. Moreover, the optomechanical coupling between the mechanical motion of the cantilever and the cavity field can be mediated by the interaction with the atom. Their couplings are demonstrated in detail by analyzing the normal-mode splitting of the mechanical motion and the optical response of the hybrid optomechanical system. It is found that double optomechanically-induced transparency can be observed in the output probe field in the presence of the mediated coupling. In particular, both the width of the splitting peaks and the separation between the two absorption dips increase with the increasing strength of the vacuum coupling and with the decreasing trapped position of the atom. These characteristics can be used to study the strong coupling between a single atom and a massive micromechanical cantilever.