Topological Materials
Hsin Lin1*
1Department of Physics, National University of Singapore, Singapore
* presenting author:Hsin Lin,
Topological materials host various novel quantum phases of electrons which are characterized by band topology and topologically protected surface states. Despite recent progress, intense world-wide research activity in search of new classes of topological materials is continuing unabated. This interest is driven by the need for materials with greater structural flexibility and tunability to enable viable applications in spintronics and quantum computing. We have used first-principles band theory computations to successfully predict many new classes of topologically interesting materials, including Bi2Se3 series, the ternary half-Heusler compounds, TlBiSe2 family, Li2AgSb-class, and GeBi2Te4 family as well as topological crystalline insulator (TCI) SnTe family and Weyl semimetals TaAs, SrSi2, and (Mo,W)Te2. I will demonstrate the Z2 topological phase transition in TlBi(Se,S)2 and an idea to adopt it to achieve high-Chern number quantum anomalous Hall insulators. Observation of novel interference patterns on the surface of TCI and Weyl semiemtals in Fourier transform scanning tunneling spectroscopy (FT-STS) will be discussed.

Keywords: Topological Insulator, first-principles calculation, scanning tunneling spectroscopy