Spin-orbit splitting of Andreev states revealed by microwave spectroscopy

ORAL

Abstract

The Josephson supercurrent that flows through a weak link between two superconductors is mediated by fermionic quasiparticle states localized at the weak link: the Andreev bound states. To explore the role of the spin of these states, we have performed their microwave absorption spectroscopy in superconducting weak links with strong spin-orbit coupling: an InAs-Al (core-full shell) epitaxially-grown nanowire. The spectra present distinctive features that we interpret as arising from zero-field spin-split Andreev states. A simple empirical model, which takes into account the Rashba spin-orbit interaction in a multichannel nanowire, explains these features and their evolution with magnetic field. Our results show that the spin of quasiparticles can be a relevant degree of freedom in Josephson weak links.

*Marie Sklodowska-Curie individual fellowship grant 705467

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Presenters

  • Leandro Tosi

    • Quantronics Group, SPEC, CEA-Saclay

Authors

  • Leandro Tosi

    • Quantronics Group, SPEC, CEA-Saclay

  • Cyril Metzger

    • Quantronics Group, SPEC, CEA-Saclay

  • Marcelo Goffman

    • Quantronics Group, SPEC, CEA-Saclay

  • Cristian Urbina

    • Quantronics Group, SPEC, CEA-Saclay

  • Hugues Pothier

    • Quantronics Group, SPEC, CEA-Saclay

  • sunghun park

    • Departamento de Materia Condensada, Universidad Autonoma de Madrid

  • Alfredo Levy Yeyati

    • Departamento de Materia Condensada, Universidad Autonoma de Madrid

  • Peter Krogstrup

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

  • Jesper Nygård

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