Engineering topological superconductivity in InAs Josephson junctions

ORAL

Abstract

Josephson junctions can be used to engineer topological superconductivity in semiconductors with strong spin-orbit coupling. Proposals to achieve this include proximitizing the edge of the material or applying a superconducting phase bias across the junction. Using superconducting quantum interference measurements on an InAs junction we demonstrate that in the trivial regime edge state transport gives rise to a SQUID-like pattern. More strikingly, we find that SQUID signal is h/e (not h/2e) periodic. While this is considered a hallmark of the topological regime, we explain how crossed Andreev states in the trivial regime can give rise to the same effect. To avoid complications arising from such trivial edges we also explore the possibility of phase biasing InAs Josephson junctions. This is predicted to significantly bring down the Zeeman field needed for a topological phase transition. We study the response to phase bias and develop tunnel probes to measure the local density of states in the junction.

*This work has been supported by funding from the Netherlands Organisation for Scientific Research (NWO), Microsoft Corporation Station Q, the Danish National Research Foundation and an ERC Synergy Grant.

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Presenters

  • Folkert De Vries

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

Authors

  • Folkert De Vries

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • Tom Timmerman

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • Viacheslav Ostroukh

    • Instituut-Lorentz, Leiden University

  • Jasper van Veen

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • Arjan Beukman

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • Fanming Qu

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • Michael Wimmer

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology
    • QuTech, Delft University of Technology

  • Minh Nguyen

    • HRL Laboratories

  • Andrey Kiselev

    • HRL Laboratories

  • Wei Yi

    • HRL Laboratories

  • Marko Sokolich

    • HRL Laboratories

  • Sergei Gronin

    • Microsoft Station Q Purdue
    • Purdue University, Station Q Purdue

  • 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

  • Candice Thomas

    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Microsoft Station Q Purdue

  • 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

  • Srijit Goswami

    • Qutech and Kavli Institute of Nanoscience, Delft University of Technology

  • 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

  • Leo Kouwenhoven

    • Microsoft Station-Q Delft, Delft University of Technology
    • Delft Univ of Tech
    • Qutech and Kavli Institute of Nanoscience and Microsoft Station Q Delft, Delft University of Technology
    • QuTech, Kavli Institute of Nanoscience, Station Q at Delft University of Technology, Delft University of Technology
    • Microsoft Station-Q at Delft University of Technology
    • Delft Univ. of Technology, Microsoft Station Q
    • Station Q Delft, Microsoft
    • Microsoft Station Q