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Nonlinear Coupling for Enhanced Readout in Circuit QED

ORAL

Abstract

Dispersive readout is the standard method of measurement of superconducting qubits, and recent experimental results have shown fidelities exceeding 99.9% in approximately 50ns [1]. Despite these advancements, dispersive readout suffers from intrinsic limitations due to multi-photon processes between the qubit and the readout resonator, which can rapidly degrade measurement fidelity [2, 3, 4].

In this talk, we present a novel readout approach using a nonlinear coupling between the qubit and readout resonator. This approach achieves high-fidelity, fast readout with similar hardware overhead compared to standard dispersive readout. We show that our scheme can surpass the performance of dispersive readout across a broad parameter space and does not require Purcell filters.

[1] P. Spring et. al., arXiv:2409.04967

[2] R. Shillito et al., Phys. Rev. Applied 18, 034031 (2022).

[3] M. F. Dumas et al., Phys. Rev. X 14, 041023 (2024)

[4] M. Khezri et al., Phys. Rev. Applied 20, 054008 (2023)

Presenters

  • Alex A Chapple

    Universite de Sherbrooke, Université de Sherbrooke

Authors

  • Alex A Chapple

    Universite de Sherbrooke, Université de Sherbrooke

  • Othmane Benhayoune Khadraoui

    Université de Sherbrooke

  • Alexandre Blais

    Université de Sherbrooke