Embedded Amplifier for Efficient Superconducting Qubit Readout, Part 2: Experiment

ORAL

Abstract

In a typical dispersive superconducting qubit readout, microwave circulators are placed between the readout cavity and the first parametric amplifier to avoid excess amplifier backaction on the qubit. The microwave losses intrinsic to these circulators and their associated wiring reduce measurement fidelity, scalability, and the viability of weak measurement-based feedback protocols. Recently, it was shown that directional amplifiers can circumvent the need for conventional circulators, enabling record high measurement efficiencies [1]. In this talk, we will discuss experimental progress toward directly embedding a qubit inside a directional amplifier to further increase measurement efficiency. In particular, we will focus on the characterization of a transmon qubit coupled to a multimode parametric system acting as an effective readout cavity with directional gain.

[1] F. Lecocq, L. Ranzani, G. A. Peterson, K. Cicak, X. Y. Jin, R. W. Simmonds, J. D. Teufel, and J. Aumentado, Physical Review Letters 126 (2021).

–

Presenters

  • Benton T Miller

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

Authors

  • Benton T Miller

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

  • Lindsay Orr

    Karlsruhe Institute of Technology, Karlsruhe Institute for Technology

  • Bradley D Hauer

    National Institute of Standards and Technology, Boulder

  • Katarina Cicak

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

  • Raymond W Simmonds

    National Institute of Standards and Technology, Boulder

  • José Aumentado

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Quantum Circuits, Inc, Quantum Circuits, Inc.

  • John D Teufel

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

  • Anja Metelmann

    Karlsruhe Institute of Technology, Karlsruhe Institute for Technology

  • Florent Lecocq

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