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Gate tunable multi-terminal Josephson effect

ORAL

Abstract

Junctions of more than two superconducting terminals are required for implementing braiding operations on Majorana fermions. Moreover, such multi-terminal Josephson Junctions (JJ) were predicted to support topological state and host zero-energy quasiparticles. Unlike conventional two-terminal JJs where the value of critical current is a number, the multi-terminal JJs exhibit a novel feature – the critical current contour (CCC) [1]. We report the measurement of non-trivial CCC shapes as a function of gate voltage and magnetic field in hybrid semiconductor/superconductor (InAs/Al) multi-terminal JJs. Multi-terminal junctions can host two different regimes: a strong neighbor-coupling regime and a multi-terminal regime, depending on the gate voltage. The geometry of a junction is also an important factor defining the operating regime. The effect of an out-of-plane magnetic field indicates an observation of the Fraunhofer interference pattern in multi-terminal JJs.
[1] N. Pankratova, H. Lee et al., “The multi-terminal Josephson effect”, arXiv:1812.06017

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Presenters

  • Natalia Pankratova

    University of Maryland, College Park

Authors

  • Natalia Pankratova

    University of Maryland, College Park

  • Hanho Lee

    University of Maryland, College Park

  • Roman Kuzmin

    University of Maryland, College Park

  • Kaushini S Wickramasinghe

    New York University, Physics, New York University, University of Maryland, College Park, Center for Quantum Phenomena, New York University, New York Univ NYU, Department of Physics, New York University

  • Maxim G Vavilov

    University of Wisconsin-Madison, Department of Physics, University of Wisconsin - Madison, University of Wisconsin - Madison

  • Javad Shabani

    Department of Physics, New York University, New York University, Physics, New York University, New York Univ NYU, Center for Quantum Phenomena, New York University, Center for Quantum Phenomena, NYU

  • Vladimir Manucharyan

    Physics, Univ of Maryland-College Park, University of Maryland, College Park, University of Maryland - College Park, University of Maryland