Planar MgB$_{2}$ superconductor-normal metal-superconductor Josephson junctions

ORAL

Abstract

We have fabricated planar superconductor-normal metal-superconductor (SNS) MgB$_{2}$ Josephson junctions using MgB$_{2}$ films grown by hybrid physical chemical vapor deposition (HPCVD). The junctions exhibit resistively-shunted-junction-like (RSJ-like) current-voltage characteristics up to 31~K. Ac Josephson effect was observed and the behavior of the Shapiro steps are in good agreement with theoretical predictions. The magnetic field modulation of the critical current also agrees with the thin film planar junction behavior. The junction's behavior can be described by Likharev's proximity effect model with rigid boundary at dirty limit. A dc SQUID with modulation depth of 45~\textit{$\mu $}V at 29~K has been demonstrated. This work is supported by ONR, NSF, and AFOSR.

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Authors

  • Ke Chen

  • Y. Cui

  • Qi Li

    Department of Physics, Pennsylvania State University, PA16801, Physics, The Pennsylvania State University, Department of Physics, The Pennsylvania State University, University Park, Pennsylvania State University

  • Xiaoxing Xi

    Department of Physics and Department of Materials Science and Engineering, The Pennsylvania State University, Department of Physics and Department of Materials Sciene and Engineering, The Pennsylvania State University, University Park, The Pennsylvania State University, Penn State University

  • Shane Cybart

    Department of Physics, University of California, San Diego

  • R. C. Dynes

    Department of Physics, University of California, Berkeley

  • X. Wen

  • Joan Redwing

    Department of Materials Science and Engineering, The Pennsylvania State University, Department of Materials Sciene and Engineering, The Pennsylvania State University, University Park, The Pennsylvania State University