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