Qubit State Measurement using the Josephson Photomultiplier

ORAL

Abstract

We describe results of high-fidelity qubit state measurement based on microwave photon counting. The protocol involves mapping the qubit state onto high-contrast microwave cavity pointer states in a linear readout resonator followed by subsequent photodetection using the Josephson Photomultiplier (JPM). Our technique provides access to the classical binary outcome of qubit state measurement at the millikelvin stage of a dilution refrigerator and does not use any non-reciprocal components between the qubit and JPM. We exploit the intrinsic damping of the JPM to “clean up” following photodetection so that the measurement is highly QND. This approach is well-suited for integration with proximal cryogenic digital logic.

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Presenters

  • Alexander Opremcak

    Univ of Wisconsin, Madison, Physics, University of Wisconsin Madison, University of Wisconsin-Madison

Authors

  • Alexander Opremcak

    Univ of Wisconsin, Madison, Physics, University of Wisconsin Madison, University of Wisconsin-Madison

  • Ivan Pechenezhskiy

    Univ of Wisconsin, Madison

  • Caleb Howington

    Physics, Syracuse University, Physics, Syracuse Univ, Syracuse Univ, Syracuse University

  • Bradley Christensen

    Univ of Wisconsin, Madison

  • Konstantin Nesterov

    University of Wisconsin-Madison, Univ of Wisconsin, Madison

  • Maxim Vavilov

    Physics, University of Wisconsin-Madison, Department of Physics, University of Wisconsin-Madison, Univ of Wisconsin, Madison, University of Wisconsin-Madison, Physics, University of Wisconsin Madison

  • Frank Wilhelm

    Theoretical Physics, Saarland University, Physics, Univ des Saarlandes, Saarland University, Theoretical physics, Saarland university, Theoretical Physics, Universität des Saarlandes

  • Britton Plourde

    Syracuse Univ, Physics, Syracuse Univ, Syracuse University, Physics, Syracuse University

  • Robert McDermott

    Univ of Wisconsin, Madison, Physics, University of Wisconsin - Madison, Physics, University of Wisconsin-Madison, Physics, Univ of Wisconsin-Madison, Physics, University of Wisconsin Madison, University of Wisconsin-Madison