Anomalous optical properties of a multiband metal due to thermal redistribution: The case of SrMnSb$_{\mathrm{2}}$

ORAL

Abstract

We report an optical spectroscopic study of SnMnSb$_{\mathrm{2}}$, a low carrier density metal. As temperature is decreased, our measurements reveal a large increase in the free carrier plasma frequency, which is unusual for a metal. This seemingly anomalous behavior can be accounted for using a `three band' model of the multiband electronic structure of SrMnSb$_{\mathrm{2}}$ that includes two conduction bands and one valence band close to the Fermi level. The temperature dependence of the low-lying interband optical transitions and the Hall number can also be understood using our model. Our results provide a possible explanation for the puzzling optical properties that have been reported in a number of topical low carrier density metals and semimetals.

–

Authors

  • H. J. Park

    • CCES-IBS & Dep. of Physics and Astronomy, SNU

  • LUKE J. SANDILANDS

    • CCES-IBS & Dep. of Physics and Astronomy, SNU

  • J. S. You

    • Dep. of Physics, POSTECH

  • Hyo Seok JI

    • Dep. of Chemistry, POSTECH

  • C. H. Sohn

    • CCES-IBS & Dep. of Physics and Astronomy, SNU

  • J. W. Han

    • Dep. of Physics and Photon Science, School of Physics and Chemistry, GIST

  • S. J. Moon

    • Dep. of Physics, Hanyang Univ.

  • K. W. Kim

    • Dep. of Phyisics, Chungbuk National Univ.

  • Ji Hoon Shim

    • Pohang University of Science and Technology
    • Dep. of Chemistry & Division of Advanced Nuclear Engineering, POSTECH

  • Jun Sung Kim

    • Dep. of Physics, POSTECH

  • Tae Won Noh

    • Seoul National University
    • CCES-IBS & Dep. of Physics and Astronomy, SNU