Quantum transport in Dirac semimetal Cd3As2 thin films

ORAL

Abstract

The synthesis of thin films of the Dirac semimetal (DSM) Cd3As2 by molecular beam epitaxy (MBE) provides an attractive avenue for studying quantum transport in a DSM as a function of quantum confinement and chemical potential. We have used MBE to grow thin films of Cd3As2 on GaAs (111)B substrates with a GaSb buffer layer. The film thickness is varied in the range of 7 nm – 20 nm. Atomic force microscopy, x-ray diffraction, and electrical transport show that the films have good crystalline quality (root mean square surface roughness ~ 1.5 nm and full-width half maximum of rocking curves ~ 0.12°) and reasonable electron mobility (5,000 – 40,000 cm2/V.s at 4.2 K). We have studied Shubnikov-de Haas oscillations in lithographically patterned top gated Hall bar devices as a function of gate voltage, temperature, and magnetic field magnitude/angle. We interpret these quantum oscillation data in concert with in vacuo angle-resolved photoemission spectroscopy and first-principles calculations to gain insight into the Fermi surface of these DSM thin films.

*Supported by the Institute for Quantum Matter under DOE EFRC grant DE-SC0019331, the nCORE/SMART Center, and the Penn State Two-Dimensional Crystal Consortium-Materials Innovation Platform (2DCC-MIP) under NSF Grant No. DMR-1539916

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Presenters

  • Run Xiao

    • Pennsylvania State University
    • Physics, Pennsylvania State University

Authors

  • Run Xiao

    • Pennsylvania State University
    • Physics, Pennsylvania State University

  • Sayak Ghosh

    • Cornell University

  • Arpita Mitra

    • Pennsylvania State University

  • Wilson Yanez

    • Pennsylvania State University
    • Physics, Pennsylvania State University

  • Timothy S Pillsbury

    • Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University
    • The Pennsylvania State University

  • Yawen Fang

    • Cornell University

  • Juan Chamorro

    • Johns Hopkins University

  • Santu Baidya

    • Rutgers University
    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University

  • Tanya Berry

    • Johns Hopkins University
    • The Johns Hopkins University

  • David Vanderbilt

    • Rutgers University, New Brunswick
    • Rutgers University
    • Physics, Rutger Univeristy
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA

  • Yi Li

    • Johns Hopkins University

  • Tyrel McQueen

    • Johns Hopkins University
    • The Johns Hopkins University
    • Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University

  • Brad Ramshaw

    • Cornell University
    • Physics, Cornell University

  • Nitin Samarth

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University
    • The Pennsylvania State University