Quantum Nondemolition Photon Counting With a Hybrid Electromechanical Probe

Quantum nondemolition (QND) measurements of photons is a much pursued endeavor in the field of quantum optics and quantum information processing. Here we propose a novel hybrid optoelectromechanical platform that integrates a cavity optomechanical system with a single electron transistor for QND photon counting. Building upon a mechanical-mode-mediated nonperturbative dispersive coupling between electrons and photons, our protocol performs the QND photon counting measurement by means of the current-voltage characteristics of the single electron transistor. In particular, we show that the peak voltage shift of the differential conductance is linearly dependent on the photon occupation number, thus providing a sensitive measure of the photon number, especially in the strong optomechanical coupling regime. Given that our proposed hybrid system is compatible with state-of-the-art experimental techniques, we discuss immediate implementations and anticipate applications in quantum optics and polariton physics.