Using first-principles calculations within density functional theory, we explore the feasibility of converting ternary half-Heusler compounds into a new class of three-dimensional topological insulators (3DTI). We demonstrate that the electronic structure of unstrained LaPtBi as a prototype system exhibits distinct band-inversion feature. The 3DTI phase is realized by applying a uniaxial strain along the [001] direction, which opens a bandgap while preserving the inverted band order. A definitive proof of the strained LaPtBi as a 3DTI is provided by directly calculating the topological Z2 invariants in systems without inversion symmetry. We discuss the implications of the present study to other half-Heusler compounds as 3DTI, which, together with the magnetic and superconducting properties of these materials, may provide a rich platform for novel quantum phenomena.
@article{arxiv.1008.0057,
title = {Half-Heusler Compounds as a New Class of Three-Dimensional Topological Insulators},
author = {Di Xiao and Yugui Yao and Wanxiang Feng and Jun Wen and Wenguang Zhu and Xingqiu Chen and G. Malcolm Stocks and Zhenyu Zhang},
journal= {arXiv preprint arXiv:1008.0057},
year = {2010}
}