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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