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.

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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