Type: Article
Publication Date: 2017-03-02
Citations: 13
DOI: https://doi.org/10.1038/srep43666
Abstract The quantum spin Hall insulators predicted ten years ago and now experimentally observed are instrumental for a break- through in nanoelectronics due to non-dissipative spin-polarized electron transport through their edges. For this transport to persist at normal conditions, the insulators should possess a sufficiently large band gap in a stable topological phase. Here, we theoretically show that quantum spin Hall insulators can be realized in ultra-thin films constructed from a trivial band insulator with strong spin-orbit coupling. The thinnest film with an inverted gap large enough for practical applications is a centrosymmetric sextuple layer built out of two inversely stacked non-centrosymmetric BiTeI trilayers. This nontrivial sextuple layer turns out to be the structure element of an artificially designed strong three-dimensional topological insulator Bi 2 Te 2 I 2 . We reveal general principles of how a topological insulator can be composed from the structure elements of the BiTe X family ( X = I, Br, Cl), which opens new perspectives towards engineering of topological phases.