Scanning tunneling spectroscopy of Dirac electrons in doped SnTe

ORAL

Abstract

SnTe has attracted interest both as a ferroelectric material and because it is a topological crystalline insulator with Dirac surface states. However, due to the propensity for Sn vacancies, the Dirac point is generally well above the Fermi level in as-grown SnTe crystals and therefore difficult to experimentally access. Here we study doped SnTe samples using a scanning tunneling microscope. Quasi-particle interference measurements reveal the surface state dispersion and show that the Dirac point is shifted closer to the Fermi level. We further explore the behavior of these Dirac electrons in the presence of a magnetic field. This regime is particularly interesting in SnTe because it has multiple degenerate valleys, each of which lacks two-fold rotational symmetry. Therefore, valley polarized electronic states at odd integer filling factors are anticipated to possess an in-plane dipole moment, giving rise to a quantum Hall ferroelectric phase.

*We would like to thank the support from ARO, NSF-DMR and NSF-MRSEC.

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Presenters

  • Yuwen Hu

    • Joseph Henry Laboratories & Department of Physics, Princeton University

Authors

  • Yuwen Hu

    • Joseph Henry Laboratories & Department of Physics, Princeton University

  • Dillon Wong

    • Princeton University
    • Joseph Henry Laboratories & Department of Physics, Princeton University
    • UCB
    • Physics, Princeton University
    • Univ of California - Berkeley

  • Benjamin Feldman

    • Joseph Henry Laboratories & Department of Physics, Princeton University
    • Princeton University

  • Mallika Randeria

    • Joseph Henry Laboratories & Department of Physics, Princeton University
    • Princeton University

  • Hao Ding

    • Joseph Henry Laboratories & Department of Physics, Princeton University
    • Princeton University

  • Satya Kushwaha

    • Department of Chemistry, Princeton University
    • Princeton Univ

  • Robert Cava

    • Department of Chemistry, Princeton University
    • Princeton
    • Princeton University
    • Chemistry, Princeton Univ
    • Princeton Univ

  • Ali Yazdani

    • Physics department, Princeton Univ
    • Joseph Henry Laboratories & Department of Physics, Princeton University
    • Physics Department, Princeton University
    • Physics, Princeton University
    • Princeton University