Current-Phase Relation in Locally Gated InAs Nanowire Josephson Junctions

ORAL

Abstract

Nanowire-based Josephson junctions are candidates for superconducting qubit infrastructures and schemes for topological quantum computation, as well as model systems for fundamental questions in junctions with one to several current-carrying modes. In this talk we report measurements of nanowire Josephson junctions in which we tune the device behavior via local electrostatic gates. Using a scanned SQUID (Superconducting QUantum Interference Device) sensor, we monitor the current-phase relation (CPR) of the junction as it is gate-tuned into several different regimes. At the most positive gate voltages, the CPR is characterized by several highly transmitting modes. As the gate voltage becomes more negative, depleting the junction, the mode transmission probabilities are tuned and the CPR evolves through several resonant peaks. In certain gate configurations, we also find evidence for interactions and localized states forming in the junction. These observations will influence future gating schemes for hybrid nanowire junctions, and will inspire theoretical studies of CPR in real devices.

*We acknowledge funding from DOE, NSF, Microsoft, and the Danish National Research Foundation.

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Presenters

  • Sean Hart

    • Stanford Univ

Authors

  • Sean Hart

    • Stanford Univ

  • Zheng Cui

    • Stanford Univ

  • Eric Spanton

    • University of California - Santa Barbara
    • Stanford Univ
    • California Nanosystems Institute, University of California, Santa Barbara
    • California Nanosystems Institute, University of California
    • Univ of California - Santa Barbara

  • Mingtang Deng

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

  • Gerbold Menard

    • University of Copenhagen

  • Peter Krogstrup

    • 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
    • University of Copenhagen

  • Charles Marcus

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

  • Kathryn Moler

    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory
    • Physics and Applied Physics, Stanford University
    • Applied Physics, Stanford Univ
    • Stanford Univ