Optical properties of highly resistive Bi$_2$Te$_2$Se

ORAL

Abstract

Topological insulators are characterized by strong spin-orbit coupling, producing metallic surface states while the bulk remains insulating. Experimental observations of surface states in transport and optical measurements have been obstructed by bulk contributions due to sample defects, placing the Fermi level in the bulk energy gap. Bi$_2$Te$_2$Se (BTS), a three-dimensional topological insulator, has recently been shown to exhibit a bulk resistivity larger than any other topological insulator measured to date. However, quantum oscillations are still observed, and attributed to the surface states. In this talk I will present the optical properties of BTS, obtained by broadband FTIR spectroscopy combined with ellipsometry, over a range of 20 - 45,000 $cm^{-1}$, as well as the Raman spectrum of BTS.

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Authors

  • Anjan Reijnders

    • University of Toronto
    • Department of Physics and Institute for Optical Sciences, University of Toronto

  • Shu Yang Frank Zhao

    • University of Toronto
    • Department of Physics and Institute for Optical Sciences, University of Toronto

  • Louise Niemeyer

    • University of Toronto

  • Raphael Bouskila

    • University of Toronto

  • H. J. Cho

    • University of Toronto

  • Seyedyara Mohajerani

    • University of Toronto

  • Luke J. Sandilands

    • University of Toronto

  • Robert Cava

    • Princeton University

  • Kenneth Burch

    • University of Toronto
    • Department of Physics and Institute of Optical Sciences, U. of Toronto