Appearance of above the gap resonances in dirty Josephson junctions with epitaxial contact

ORAL

Abstract

In Josephson junctions, when the separation of the superconducting contacts is made long enough, the system can be approximated with two superconducting-normal metal junctions connected with a normal link. In devices fabricated on InAs-Al materials, we observe oscillations of conductance with driving bias above the superconducting gap. The frequency of conductance oscillations as a function of the bias is determined by the geometric properties of the junction. We interpret these geometric oscillations (GO) in interference of quasi-particles with energies above the superconductivity gap. This can be compared with a simple quantum mechanical problem involving a particle in the box where the states with energy above the box wall solely gain a phase shift as they pass over the box potential. In the case of GO the variation of the superconducting gap size affect the phase of the quasi-particles as they pass through. We compare our data with our theoretical model and find agreement in dependence of the data to bias, magnetic field and temperature.

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Presenters

  • Shahrzad Zare

    Physics, New York University

Authors

  • Shahrzad Zare

    Physics, New York University

  • William Andrew Mayer

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

  • Foster H Sabatino

    Physics, New York University

  • Cody Youmans

    City College of New York, Physics, City College of City University of New York

  • 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

  • Joseph Yuan

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

  • Matthieu Dartiailh

    Physics, New York University, Center for Quantum Phenomena, Department of Physics, New York University, Laboratoire Pierre Aigrain UMR 8551, Ecole normale Supérieure - PSL Research university, CNRS, Université Pierre et Marie Curie - Sorbonne Universités, Université Paris Dider

  • Aaron Somoroff

    University of Maryland, College Park, University of Maryland-College Park, Physics, City College of City University of New York, University of Maryland - College Park

  • Pouyan Ghaemi Mohammadi

    Physics, The City College of New York, CUNY, Physics, City College of City University of New York, City College of New York, Physics, City College of New York,New York, NY 10031

  • 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