Effective g-factor in Majorana Wires

ORAL

Abstract

We use the effective g-factor of subgap states, g*, in hybrid InAs nanowires with an epitaxial Al shell to investigate how the superconducting density of states is distributed between the nanowire core and the shell. We find a step-like reduction of g* and improved hard gap with reduced carrier density in the nanowire, controlled by gate voltage. These observations are relevant for Majorana devices, which require tunable carrier density and g* exceeding the g-factor of the proximitizing superconductor. Additionally, we observe the closing and reopening of a gap in the subgap spectrum coincident with the appearance of a zero-bias conductance peak. Finally, more recent results from different device geometries are discussed.

*This research was supported by Microsoft Research, Project Q, the Danish National Research Foundation, the Villum Foundation, and the European Commission.

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Presenters

  • Saulius Vaitiekenas

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

Authors

  • Saulius Vaitiekenas

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

  • Ming Deng

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

  • Jesper Nygard

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

  • Peter Krogstrup

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

  • 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