Thermal properties and overheating of the superconductor-quantum Hall interfaces

ORAL

Abstract

Low-frequency noise measurements have been successfully used to probe such phenomena as the fractional charges and the quanta of heat conduction of fermions or anyons in the quantum Hall (QH) regime. Here we study the excess noise at the interface of a superconducting film and an encapsulated graphene in the QH regime. We find that the primary source of the excess noise is local heating, which allows one to convert the noise to electron temperature using Johnson-Nyquist noise calibration. As the magnetic field is increased, the temperature of the interface is reduced, eventually approaching the behavior expected for a normal metal. We further use our sample to study the heat conductivity across the superconducting film subject to a high magnetic field.

*The measurements by L.Z., Z.I., and T.F.Q.L., were supported by the NSF Award DMR-2004870. The setup development by T.F.Q.L., Z.I., L.Z. and G.F. was supported by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy, under Award No. DE-SC0002765. F.A. was supported by a URC grant at Appalachian State University. K.W. and T.T. acknowledge support from JSPS KAKENHI (Grant Numbers 19H05790, 20H00354, and 21H05233). The sample fabrication was performed in part at the Duke University Shared Materials Instrumentation Facility (SMIF), a member of the North Carolina Research Triangle Nanotechnology Network (RTNN), which is supported by the National Science Foundation (Grant ECCS-1542015) as part of the National Nanotechnology Coordinated Infrastructure (NNCI).

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Presenters

  • Zubair Iftikhar

    • Duke University

Authors

  • Zubair Iftikhar

    • Duke University

  • Trevyn Larson

    • Duke University

  • Lingfei Zhao

    • Duke University

  • Gleb Finkelstein

    • Duke University

  • Francois Amet

    • Appalachian State University

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science
    • Kyoto University
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute For Materials Science
    • NIMS
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan