Half-Heusler compounds as a new class of three-dimensional topological insulators

• Published in: Physical review letters Vol. 105; no. 9; p. 096404
• Main Authors: Xiao, Di, Yao, Yugui, Feng, Wanxiang, Wen, Jun, Zhu, Wenguang, Chen, Xing-Qiu, Stocks, G Malcolm, Zhang, Zhenyu
• Format: Journal Article
• Language: English
• Published: United States 27.08.2010
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.105.096404

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 a distinct band-inversion feature. The 3DTI phase is realized by applying a uniaxial strain along the [001] direction, which opens a band gap 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.