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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.

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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