Multi-terminal Josephson effect in epitaxial InAs/Al superconductor/semiconductor devices I: current-biased measurements

ORAL

Abstract

Junctions of more than two topological superconductors are typically required for implementing braiding operations on Majorana fermions [1]. Here we report the first realization of 3- and 4-terminal Josephson junctions fabricated from a Majorana-compatible hybrid InAs/Al epitaxially-grown heterostructure [2]. We observed several novel phenomena: interaction of intersecting supercurrents, multi-terminal Fraunhofer effect in a magnetic field, and out-of-equilibrium multiple Andreev reflections (MAR) at bias voltages far exceeding the gap of Al. The data in a large number of channels regime can be modeled using random matrix circuit theory of superconducting transport. Progress towards realizing the phase-control of zero-energy quasiparticle states, predicted in such structures in the absence of Zeeman fields [3,4,5], will be discussed.
[1] J. Alicea, Phys. Rev. B 81, 125318 (2010);
[2] K. Wickramasinghe et al., arXiv:1802.09569 (2018);
[3] R. Riwar et al., Nat. Commun. 7, 11167 (2016);
[4] B. Van Heck et al., Phys. Rev. B 90, 155450;
[5] H. Xie et al., Physical Review B 96 (2017)

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Presenters

  • Hanho Lee

    • University of Maryland, College Park

Authors

  • Hanho Lee

    • University of Maryland, College Park

  • Natalia Pankratova

    • University of Maryland, College Park

  • Roman Kuzmin

    • University of Maryland, College Park

  • Kaushini Wickramasinghe

    • University of Oklahoma
    • Department of Physics, New York University
    • Physics, New York University
    • Physics, University of Maryland, College Park
    • Center for Quantum Phenomena, Department of Physics, New York University
    • University of Maryland, College Park

  • Alex Levchenko

    • University of Wisconsin-Madison
    • University of Wisconsin, Madison, WI, USA

  • Maxim Vavilov

    • University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin - Madison
    • University of Wisconsin, Madison
    • Physics, University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin - Madison, Madison, WI 53706
    • University of Wisconsin-Madison

  • Javad Shabani

    • Department of Physics, New York University
    • Physics, New York University
    • Center for Quantum Phenomena, Department of Physics, New York University
    • Center for Quantum Phenomena, New York University
    • New York University
    • Physics, Harvard University

  • Vladimir Manucharyan

    • Department of Physics, University of Maryland
    • University of Maryland, College Park
    • University of Maryland-College Park
    • Physics, University of Maryland, College Park
    • Department of Physics, University of Maryland, College Park, MD 20742
    • University of Maryland - College Park