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.

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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