Robust measurement of a qubit encoded in the bosonic mode of a superconducting cavity

ORAL

Abstract

Reliable single-shot readout is a necessary DiVincenzo criterion for quantum computation. The readout fidelity of any two-level system is bounded by the rate of a single error. In contrast, if qubit states are encoded using higher occupation levels of a bosonic mode, a single error does not completely destroy the information: the basis states are still distinguishable. We present experimental results for a high-fidelity readout scheme in which information is encoded in higher photon numbers of a superconducting cavity. By performing repeated QND measurements utilizing an ancillary transmon, we can asymptotically reduce the effects of both photon loss and infidelity of individual measurements. We demonstrate the capability of high-fidelity state readout in our system and discuss limits on the achievable fidelity.

*This research was supported by the Army Research Office under Grant No.W911NF-14-1-0011.

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Presenters

  • Sal Elder

    • Dept. of Applied Physics, Yale University
    • Yale University

Authors

  • Sal Elder

    • Dept. of Applied Physics, Yale University
    • Yale University

  • Christopher Wang

    • Dept. of Applied Physics, Yale University
    • Yale University

  • Connor Hann

    • Dept. of Applied Physics, Yale University
    • Yale University

  • Kevin Chou

    • Applied Physics, Yale University
    • Physics and Applied Physics, Yale University
    • Dept. of Applied Physics, Yale University
    • Yale University
    • Yale Univ

  • Christopher Axline

    • Applied Physics, Yale University
    • Physics and Applied Physics, Yale University
    • Dept. of Applied Physics, Yale University
    • Departments of Applied Physics and Physics, Yale University

  • Luke Burkhart

    • Applied Physics, Yale University
    • Physics and Applied Physics, Yale University
    • Department of Applied Physics, Yale Univ
    • Yale University
    • Dept. of Applied Physics, Yale University
    • Departments of Applied Physics and Physics, Yale University

  • Luigi Frunzio

    • Yale University
    • Applied Physics, Yale University
    • Physics and Applied Physics, Yale University
    • Applied Physics, Yale Univ
    • Dept. of Applied Physics, Yale University
    • Department of Applied Physics, Yale Univ
    • Yale Univ
    • Departments of Applied Physics and Physics, Yale University

  • Liang Jiang

    • Yale University
    • Applied Physics, Yale University
    • Yale
    • Dept. of Applied Physics, Yale University

  • Robert Schoelkopf

    • Yale University
    • Applied Physics, Yale University
    • Physics and Applied Physics, Yale University
    • Applied Physics, Yale Univ
    • Dept. of Applied Physics, Yale University
    • Departments of Applied Physics and Physics, Yale University