Measurement of Single Phonons with Single Photons

There has been great recent progress in controlling the quantum behavior of nanomechanical resonators. In this project, we aim to extend such control to the strongly quantum regime in which a single photon can be used to either read out or act back on a single phonon. To do so, we will use a superconducting device, the Cooper pair transistor, as a charge-tunable inductance embedded in a superconducting microwave cavity. By coupling the transistor to a nanomechanical resonator, we plan to use resonator motion at the level of a single phonon to shift the resonant frequency of the cavity. This capability should allow us to investigate strongly non-linear quantum interactions of light with matter, with implications for quantum measurement and information science. Our group collaborates closely with the group of Miles Blencowe on this project.