paper

Topological insulators with perfect vacancy superstructure and possible implications for iron chalcogenide superconductors

arXiv:1103.2538

Abstract

Motivated by the newly-discovered intercalated iron chalcogenide superconductors, we construct a single orbital tight-binding model for topological insulators on the square lattice with a perfect vacancy superstructure. We find that such lattice structure naturally accommodates a non-vanishing geometry phase associated with the next-nearest-neighbor spin-orbit interaction. By calculating the bulk band structures and the finite stripe edge states, we show that the topological insulator phases can be tuned at certain electron fillings in a wide range of the model parameters. The possible implications of these results for the iron deficient compounds $(A, T l)_{y} F e_{2 - x} S e_{2}$ have been discussed.

4 pages, 6 figures