Speaker: Emily Pritchett, Institute for Quantum Computing, University of Waterloo
Abstract: Superconducting devices have enabled many experimental demonstrations of on-chip quantum optics in the microwave regime. While microwave fields are usually detected by linear amplification, detection of single low-energy microwave photons remains a challenge to experimental reproduction of quantum optical effects that require photon counting. We analyze the use of single current biased Josephson junctions as Josephson photomultipliers (JPMs) for microwave photon counting. By analyzing the backaction of a switching event in the junction, we show that JPMs are close to binary detectors responding only to the presence or absence of resonant photons. We discuss applications of a microwave photon counter, including on-chip demonstration of the Hanbury-Brown Twiss effect and efficient state tomography.