Surface electronic structure of topological Kondo insulator candidate SmB6: a high-resolution ARPES study

ORAL

Abstract

The Kondo insulator SmB6 has been known to exhibit low temperature transport anomaly and has recently attracted attention as a new topological insulator candidate. By combining low temperature and high resolution of the laser-based ARPES, for the first time, we probe the surface electronic structure of the anomalous conductivity regime. We observe that the bulk bands exhibit a Kondo gap of 14 meV and identify in-gap low-lying states within 4 meV of the Fermi level on the surface of this material. The low-lying states are found to form electron-like Fermi surface pockets that enclose the X and the $\Gamma$ points of the surface BZ. These states disappear as temperature is raised in correspondence with the complete disappearance of the 2D conductivity channels. While the topological nature of the in-gap metallic states cannot be ascertained, our measurements are consistent with the predicted first-principle topological Kondo insulator phase in this material.

*This work is primarily supported by U.S. DOE and Princeton University.

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Authors

  • Nasser Alidoust

    • Princeton University
    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • Madhab Neupane

    • Princeton University, USA
    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • Su-Yang Xu

    • Princeton University
    • Dept. of Physics, Princeton University, USA
    • Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • Chang Liu

    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • Ilya Belopolski

    • Dept. of Physics, Princeton University, USA
    • Princeton University
    • Dept. of Physics, Princeton University, NJ, USA

  • Guang Bian

    • University of Illinois at Urbana-Champaign
    • Department of Physics, Princeton University
    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • M. Zahid Hasan

    • Princeton Univ
    • Princeton University
    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • T. Kondo

    • ISSP, University of Tokyo, Japan

  • S. Shin

    • ISSP, University of Tokyo, Japan

  • T.-R. Chang

    • Dept. of Physics, National Tsing Hua University, Taiwan

  • H.-T. Jeng

    • Dept. of Physics, National Tsing Hua University, Taiwan

  • L. Balicas

    • NHMFL, FL, USA

  • T. Durakiewicz

    • LANL, NM, USA

  • H. Lin

    • Dept. of Physics, Northeastern University, MA, USA

  • A. Bansil

    • Dept. of Physics, Northeastern University, MA, USA

  • D.-J. Kim

    • Dept. of Physics and Astronomy, UC Irvine, CA, USA

  • Z. Fisk

    • Dept. of Physics and Astronomy, UC Irvine, CA, USA