An Architecture for High-Fidelity, Robust Two-Qubit Fluxonium Gates with a Transmon Coupler

ORAL

Abstract

Qubit lifetimes and weak anharmonicities in superconducting transmon-based quantum computers are leading causes of gate infidelity. The fluxonium qubit is a promising alternative to transmons, with coherence times reaching milliseconds and anharmonicities of several gigahertz. In this work, we present an architecture consisting of fluxonium qubits coupled via a tunable-transmon coupler (FTF, for fluxonium-transmon-fluxonium). FTF provides two very important benefits: (1) it allows for stronger couplings for non-computational state gates, and (2) suppresses the static ZZ down the kHz levels without requiring strict parameter matching. We take advantage of these strong couplings by performing a microwave-activated CZ gate, achieving high-fidelities with clear paths forward toward 99.9%. Furthermore, the frequency at which the gate is driven can be tuned over a large range, corresponding to the coupler spectrum.

*This research is funded by the U.S. Army Research Office Grant No. W911NF-14-1-0682, by the Under Secretary of Defense for Research and Engineering under Air Force Contract No. FA8702-15-D-0001, and by an IBM PHD fellowship. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the USDR&E, USAF, or ARO.

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Presenters

  • Leon Ding

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

Authors

  • Leon Ding

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • Max Hays

    • Massachusetts Institute of Technology (MIT)
    • MIT
    • Massachusetts Institute of Technology

  • Youngkyu Sung

    • Massachusetts Institute of Technology MIT

  • Bharath Kannan

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • Junyoung An

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

  • Agustin Di Paolo

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology (MIT)

  • Roni Winik

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

  • Kate Azar

    • MIT Lincoln Laboratory

  • Thomas M Hazard

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory

  • David K Kim

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory

  • Bethany M Niedzielski

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory

  • Alexander Melville

    • MIT Lincoln Laboratory

  • Mollie E Schwartz

    • MIT Lincoln Laboratory

  • Jonilyn L Yoder

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory

  • Devin L Underwood

    • IBM TJ Watson Research Center
    • IBM Quantum

  • Terry P Orlando

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • Simon Gustavsson

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • Jeffrey A Grover

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology (MIT)
    • Massachusetts Institute of Technology

  • Kyle Serniak

    • MIT Lincoln Laboratory

  • William D Oliver

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology (MIT), MIT Lincoln Laboratory
    • Massachusetts Institute of Technology (MIT)
    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology, MIT Lincoln Laboratory