The Topological Phase of Polar Semiconductors BiTeX (X=I, Cl)
1Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:Peng-Jen Chen,
The talk will focus on the topological phase of the polar semiconductors BiTeX (X=I, Cl). While the topological phase transition under pressure in BiTeI has been theoretically proposed and experimentally confirmed, it remains unclear whether BiTeCl is a topological insulator or not. Here I will give a brief introduction to the topological phase transition in BiTeI and the controversial results in BiTeCl from experimental and theoretical works. A scenario based on the overscreening in density functional theory and electron-phonon renormalization is given to explain the inconsistent topological phase of BiTeCl obtained from experiment and theory.

Keywords: topological insulators, polar semiconductors