Exchange coupling of spin qubits via a multielectron quantum dot

ORAL

Abstract

We present a theoretical description for the effective exchange interaction between distant spin qubits mediated by a multielectron quantum dot. Our model is used to interpret experimentally observed exchange interactions between singlet-triplet qubits in such a configuration. We show that a non-zero spin correlation energy for the mediator dot is required to explain key features of the measured exchange profile. The competition between the standard singlet-favouring exchange and the triplet-favouring exchange results in a sweet-spot where the interaction is resistant to charge noise on gate voltages. We argue that multielectron quantum dots are a promising avenue for fast, noise-resistant coupling of spin qubits.

*This work was supported by the Army Research Office, the Innovation Fund Denmark, the Villum Foundation, the Danish National Research Foundation and the ARC via the Centre of Excellence in Engineered Quantum Systems (EQuS), project number CE110001013. Work at Purdue was supported by the U.S. Department o

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Presenters

  • Thomas Smith

    • Univ of Sydney
    • University of Sydney

Authors

  • Filip Malinowski

    • Univ of Copenhagen

  • Frederico Martins

    • Univ of Copenhagen

  • Thomas Smith

    • Univ of Sydney
    • University of Sydney

  • Stephen Bartlett

    • Physics, The University of Sydney
    • Univ of Sydney
    • University of Sydney

  • Andrew Doherty

    • Physics, The University of Sydney
    • Univ of Sydney
    • University of Sydney

  • Peter Nissen

    • Univ of Copenhagen

  • Saeed Fallahi

    • Purdue University
    • Physics, Purdue University
    • Purdue Univ
    • Department of Physics and Astronomy, and School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University

  • Geoffrey Gardner

    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Microsoft Station Q Purdue
    • Birck Nanotechnology Center, Purdue University
    • Purdue University, Station Q Purdue
    • Purdue Univ
    • Purdue University
    • Physics and Astronomy, Purdue University

  • Michael Manfra

    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Department of Physics and Astronomy and Microsoft Station Q Purdue, Purdue University
    • Purdue University
    • Physics, Purdue University
    • Purdue University, Station Q Purdue
    • Purdue Univ
    • Department of Physics and Astronomy, and School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University
    • Physics and Astronomy, Purdue University
    • Dept. of Physics and Astronomy, Purdue Univ

  • Charles Marcus

    • Center for Quantum Devices and Microsoft Station Q Copenhagen, Niels Bohr Institute
    • Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute
    • Niels Bohr Institute, Univ of Copenhagen
    • Univ of Copenhagen
    • University of Copenhagen

  • Ferdinand Kuemmeth

    • Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Niels Bohr Institute, Univ of Copenhagen
    • Univ of Copenhagen