High-fidelity conditional two-qubit swapping gate using tunable ancillas

ORAL

Abstract

Scalable quantum computing relies crucially on high-fidelity entangling operations. Here we demonstrate that four coupled qubits can operate as a high-fidelity two-qubit entangling gate that swaps two target qubits and adds a relative sign on the |11〉 state (ZSWAP). The gate operation is controlled by the state of two ancilla (control) qubits. The system is readily implementable with superconducting qubits, using capacitively coupled qubits arranged in a diamond-shaped architecture. By using realistic device and noise parameters from state-of-the-art superconducting qubits, we show that the conditional ZSWAP operation can be implemented with a fidelity above 0.99 in a time of about 65 ns.

*We acknowlegde support from U.S. Army Research Office Grant No. W911NF-17-S-0008, The Carlsberg Foundation, The Danish National Research Council under the Sapere Aude program, and Microsoft.

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Presenters

  • Niels Jakob Loft

    • Aarhus University
    • Department of Physics and Astronomy, Aarhus University

Authors

  • Niels Jakob Loft

    • Aarhus University
    • Department of Physics and Astronomy, Aarhus University

  • Morten Kjærgaard

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • Niels Bohr Institute
    • Research Laboratory of Electronics, Massachusetts Institute of Technology, USA

  • Lasse Bjørn Kristensen

    • Aarhus University
    • Department of Physics and Astronomy, Aarhus University
    • Department of Physics and Astronomy, Aahus University

  • Christian Kraglund Andersen

    • ETH Zurich
    • ETH Zürich
    • Department of Physics, ETH Zurich

  • Thorvald W Larsen

    • Niels Bohr Insitute, Univ of Copenhagen
    • Niels Bohr Institute
    • Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

  • Simon Gustavsson

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology, USA
    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139
    • Research Laboratory of Electronics, MIT

  • William D Oliver

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Department of Physics, Research Laboratory of Electronics, Lincoln Laboratory, Massachusetts Institute of Technology
    • MIT Lincoln Lab
    • MIT Lincoln Laboratory, Department of Physics, Massachusetts Institute of Technology
    • MIT Lincoln Laboratory
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Physics, Lincoln Laboratory, Massachusetts Institute of Technology
    • Department of Physics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Lincoln Laboratory, Physics, Massachusetts Institute of Technology
    • Dept. of Physics, Research Laboratory of Electronics, and Lincoln Lab, Massachusetts Institute of Technology, USA
    • Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, MIT Lincoln Laboratory, 244 Wood Street, Lexington, MA
    • Massachusetts Institute of Technology and MIT Lincoln Laboratory
    • Research Laboratory of Electronics, MIT Lincoln Laboratory, Department of Physics, Massachusetts Institute of Technology
    • Department of Physics, Research Laboratory of Electronics, MIT Lincoln Laboratory, Massachusetts Institute of Technology
    • Department of Physics, MIT; Research Laboratory of Electronics, MIT; MIT Lincoln Laboratory

  • Nikolaj T Zinner

    • Aarhus University
    • Department of Physics and Astronomy, Aarhus University
    • Department of Physics and Astronomy, Aahus University