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High fidelity and efficient qubit measurement using parametric protocols in a circuit-QED setup.

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Abstract

Quantum computing and communication require high-fidelity, rapid qubit state readout. Furthermore, quantum error correction necessitates quantum non-demolition (QND) measurements. While dispersive readout with static coupling is a common method, it faces limitations for QND measurement due to low readout photons, loss of photons before early-stage amplification, and qubit-cavity interactions throughout the measurement process. To overcome these challenges, we propose a device with two weakly nonlinear cavity modes and a transmon qubit, coupled by a common SQUID loop [1]. This device facilitates readout with negligible static couplings at a specific flux bias and allows tunable parametric couplings to achieve on-demand dispersive shifts, beam splitter interactions, and amplification [1-2]. Moreover, the negligible static qubit-cavity coupling eliminates the need for Purcell filters. In this talk, I will discuss our experimental progress towards qubit readout by pulse-controlling parametric processes to achieve QND measurement without compromising measurement efficiency and fidelity. By simply changing the pulse protocols in this versatile system design, one can access various readout schemes tailoring them to the specific needs of the measurements.



[1] Bryan T. Gard, Zachary Parrott, Kurt Jacobs, et al. Phys. Rev. Applied 21, 024008.

[2] T. Noh, Z. Xiao, X. Y. Jin, et al. Nature Physics 19, no. 10 (October 2023): 1445–51.

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Presenters

  • Sudhir K Sahu

    University of Massachusetts Lowell, University of Massachusetts Lowell, National Institute of Standards and Technology, National Institute of Standards and Technology, University of Massachusetts Lowell, National Institute of Standards and Technology Boulder, University of Massachusetts Lowell

Authors

  • Sudhir K Sahu

    University of Massachusetts Lowell, University of Massachusetts Lowell, National Institute of Standards and Technology, National Institute of Standards and Technology, University of Massachusetts Lowell, National Institute of Standards and Technology Boulder, University of Massachusetts Lowell

  • Zachary L Parrott

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

  • Trevyn F Larson

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

  • Benton T Miller

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

  • Anthony P McFadden

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

  • Kaixuan Ji

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

  • Tongyu Zhao

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

  • Kristen L Genter

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

  • Katarina Cicak

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology, National Institute of Standards and Technology Boulder

  • Debsuvra Mukhopadhyay

    Northwestern University

  • Florent Lecocq

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

  • Leonardo Ranzani

    Raytheon BBN Technologies

  • Archana Kamal

    Northwestern University

  • Raymond W Simmonds

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