Magnetic field and flux driven 0-π phase transition in a spinful Josephson junction

ORAL

Abstract

The coexistence of magnetism and superconductivity in a Josephson junction can lead to a 0-π phase transition. Quantum dots (QDs) can serve as spin impurities that can be controllably coupled to a superconductor (S). Here, we probe the Andreev spectrum of a hybrid S-QD-S Josephson junction by performing tunneling spectroscopy with a weakly coupled normal lead. We identify a gate-voltage-induced transition from singlet to doublet ground state, where the Andreev spectrum develops a π-phase shift. We demonstrate control of the 0−π transition using superconducting phase difference across the junction and an external magnetic field. We identify parity transitions by measuring zero-bias crossings induced by a magnetic field, phase difference, and gate voltage. This research was supported by Microsoft and the Danish National Research Foundation.

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Presenters

  • Alexander Whiticar

    • Center for Quantum Devices and Microsoft Quantum Lab Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab - Copenhagen, University of Copenhagen
    • Center for Quantum Devices, Microsoft Quantum Lab – Copenhagen and Niels Bohr Institute, University of Copenhagen

Authors

  • Alexander Whiticar

    • Center for Quantum Devices and Microsoft Quantum Lab Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab - Copenhagen, University of Copenhagen
    • Center for Quantum Devices, Microsoft Quantum Lab – Copenhagen and Niels Bohr Institute, University of Copenhagen

  • Antonio Fornieri

    • Center for Quantum Devices and Microsoft Quantum Lab Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab - Copenhagen, University of Copenhagen
    • Center for Quantum Devices, Microsoft Quantum Lab – Copenhagen and Niels Bohr Institute, University of Copenhagen

  • Felix Passmann

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

  • Abhishek Banerjee

    • Center for Quantum Devices and Microsoft Quantum Lab Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab - Copenhagen, University of Copenhagen
    • Center for Quantum Devices, Microsoft Quantum Lab – Copenhagen and Niels Bohr Institute, University of Copenhagen

  • Asbjorn Drachmann

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

  • Tiantian Wang

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

  • Candice Thomas

    • Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, Purdue University
    • Microsoft Quantum at Station Q Purdue
    • Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Purdue University
    • Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA

  • Sergei Gronin

    • Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, Purdue University
    • Microsoft Quantum at Station Q Purdue
    • Birck Nanotechnology Center and Microsoft Quantum Purdue, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
    • Microsoft Quantum Purdue

  • Geoff C Gardner

    • Purdue University
    • Birck Nanotechnology Center and Microsoft Quantum Purdue, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
    • Microsoft Quantum Purdue
    • Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Physics, Purdue University

  • Michael Manfra

    • Physics and Astronomy, Purdue Univ
    • Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, School of Materials Engineering, School of Electrical and Computer Engineering, Purdue
    • Purdue Univ
    • Purdue University
    • Microsoft Quantum at Station Q Purdue
    • Department of Physics and Astronomy, Birck Nanotechnology Center, Microsoft Quantum Purdue, School og Materials Engineering & School of Electrical and Computer Engineering, P
    • Physics and Astronomy, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA
    • Department of Physics and Astronomy, PURDUE UNIVERSITY
    • Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Physics, Purdue University

  • Charles Marcus

    • Center for Quantum Devices and Microsoft Quantum Lab Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
    • Univ of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab - Copenhagen, University of Copenhagen
    • Center for Quantum Devices, Microsoft Quantum Lab – Copenhagen and Niels Bohr Institute, University of Copenhagen
    • Microsoft Corp
    • Niels Bohr Institute, University of Copenhagen