2010/07/31 by Di Xiao, Yugui Yao, Wanxiang Feng +5 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci #physics.comp-ph #quant-ph
paper · pdf · doi:10.1103/physrevlett.105.096404
published as Phys. Rev. Lett. 105, 096404 (2010) · 4 pages, 5 figures; Phys. Rev. Lett. (in press)
arxiv created 2010/07/31 · arxiv updated 2010/10/07
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.