Realization of High-fidelity CZ and ZZ-free iSWAP Gates with a Tunable Coupler

ORAL

Abstract

High-fidelity two-qubit gates at scale are a key requirement to realize the full promise of quantum computation and simulation. The advent and use of coupler elements to tunably control two-qubit interactions has improved operational fidelity in many-qubit systems by reducing parasitic coupling and frequency crowding issues. Nonetheless, two-qubit gate errors still limit the capability of near-term quantum applications. The reason, in part, is the existing framework for tunable couplers based on the dispersive approximation does not fully incorporate three-body multi-level dynamics, which is essential for addressing coherent leakage to the coupler and parasitic longitudinal interactions during two-qubit gates. Here, we present a systematic approach that goes beyond the dispersive approximation to exploit the engineered level structure of the coupler and optimize its control. Using this approach, we experimentally demonstrate CZ and ZZ-free iSWAP gates with two-qubit interaction fidelities of 99.76 +/- 0.10 % and 99.87 +/- 0.32 %, respectively, which are close to their T1 limits.

*This research was funded in part by the U.S. Army Research Office Grant W911NF-18-1-0411 and the Assistant Secretary of Defense for Research & Engineering under Air Force Contract No. FA8721-05-C-0002.

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Presenters

  • Youngkyu Sung

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology

Authors

  • Youngkyu Sung

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Leon Ding

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

  • Jochen Braumüller

    • MIT Research Laboratory of Electronics
    • Massachusetts Institute of Technology MIT

  • Antti Vepsäläinen

    • MIT Research Laboratory of Electronics
    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Aalto University
    • Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology

  • Bharath Kannan

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology

  • Morten Kjaergaard

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • MIT

  • Amy Greene

    • MIT
    • Massachusetts Institute of Technology MIT

  • Gabriel O Samach

    • MIT Research Laboratory of Electronics, MIT Lincoln Laboratory, MIT Department of Electrical Engineering and Computer Science
    • MIT
    • Massachusetts Institute of Technology MIT

  • Chris McNally

    • MIT
    • Massachusetts Institute of Technology MIT

  • David K Kim

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory
    • Lincoln Laboratory, MIT
    • MIT - Lincoln Laboratory
    • Massachusetts Institute of Technology MIT

  • Alexander Melville

    • MIT Lincoln Lab
    • MIT Lincoln Laboratory
    • Lincoln Laboratory, MIT
    • MIT - Lincoln Laboratory

  • Bethany Niedzielski

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab
    • Lincoln Laboratory, MIT
    • MIT - Lincoln Laboratory
    • Massachusetts Institute of Technology MIT

  • Mollie Schwartz

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab
    • Lincoln Laboratory, MIT
    • MIT - Lincoln Laboratory

  • Jonilyn Yoder

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Lincoln Laboratory, MIT
    • MIT - Lincoln Laboratory
    • Massachusetts Institute of Technology MIT

  • Terry Philip Orlando

    • Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • MIT
    • Research Laboratory of Electronics and Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology
    • Department of Electrical Engineering & Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Simon Gustavsson

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • MIT Research Laboratory of Electronics
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • MIT

  • William Oliver

    • MIT Lincoln Laboratory
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, MIT Lincoln Laboratory, Department of Electrical Engineering and Computer Science
    • MIT Research Laboratory of Electronics, MIT Lincoln Laboratory, MIT Department of Electrical Engineering and Computer Science
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Lincoln Laboratory
    • MIT
    • MIT, MIT Lincoln Lab
    • MIT Lincoln Lab
    • MIT Lincoln Lab, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, and Department of Physics, Massachusetts Institute of Technology. MIT Lincoln L
    • Department of Physics, Department of Electrical Engineering & Computer Science, Research Laboratory of Electronics, MIT Lincoln Laboratory, Massachusetts Institute of Technol
    • Lincoln Laboratory, Research Laboratory of Electronics, and Department of Electrical Engineering & Computer Science, MIT