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Efficient superconducting qubit measurement with an integrated nonreciprocal amplifier

ORAL

Abstract

In a typical dispersive superconducting qubit readout, circulators are placed between the readout cavity and quantum limited amplifier to avoid amplifier backaction on the qubit. However, losses due to the circulators and associated wiring significantly reduce the measurement efficiency, limiting single-shot readout fidelity and restricting the viability of weak measurement-based feedback protocols. Using a nonreciprocal amplifier can alleviate the need for circulators, enabling a more scalable and efficient measurement chain [1]. Here we discuss the operation of an integrated system combining a transmon qubit, a readout cavity and a nonreciprocal amplifier in a 3D structure. Using either continuous wave or pulsed operation, we show that this system enables high-efficiency and low backaction qubit measurement.

[1] F. Lecocq, et al. PRL 126, 020502 (2021)

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Presenters

  • Benton T Miller

    University of Colorado, Boulder

Authors

  • Benton T Miller

    University of Colorado, Boulder

  • Florent Q Lecocq

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology, National Institute of Science and Technology

  • Bradley Hauer

    National Institute of Standards and Tech

  • Katarina Cicak

    National Institute of Standards and Technology, Boulder

  • Raymond W Simmonds

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology Boulder

  • John D Teufel

    National Institute of Standards and Technology Boulder

  • Jose Aumentado

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology