Room temperature quantum spin Hall thin film for buckled honeycomb structures of silicon, germanium, and tin

ORAL

Abstract

We have carried out first-principles calculations on buckled honeycomb structures of silicon, germanium and tin. When the spin-orbit coupling is included in the computations, these two dimensional (2D) systems are found to be in a quantum spin Hall phase with nontrivial topological invariant Z$_2$=-1, and a band gap that increases with increasng atomic number. In particular, we predict that buckled honeycomb Sn thin film is a room temperature quantum spin Hall insulator with 0.25 eV band gap.

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Authors

  • Tay-Rong Chang

    • National Tsing Hua U., Hsinchu, Taiwan

  • Hsin Lin

    • Northeastern U.

  • Horng-Tay Jeng

    • National Tsing Hua U., Hsinchu, Taiwan and Institute of Physics, Academia Sinica, Taipei, Taiwan

  • M.Z. Hasan

    • Princeton U.

  • Arun Bansil

    • Northeastern U.