Regularities of the quantum spin Hall phase formation in three-dimensional tetradymite-like topological insulator thin films

摘要

We present first-principles calculations of electronic structure and topological properties of thin films of tetradymite-like binary, ternary, and quaternary compounds. Two-dimensional topological insulators were found, including two septuple layer films of PbBi_2Te_4 with large band gap. We demonstrate that the Pb-based thin films inherit Z_2 dependence on the film thickness from the "parent" quintuple-layer compounds. An effective way to induce the topological phase transition in the trivial thin films is proposed that does not require substantial changes in the in-plane lattice parameter and surface crystal structure.