Three Dimensional Topological Insulators on the Half-Heusler Lattice

Using both tight-binding model and first-principles density functional theory, it is shown that a class of materials in the half-Heusler structure are topological insulators. Specifically, the Z2 topological index is evaluated based on the bulk magnetoelectric polarizability calculation and the surface-band structure is also obtained explicitly. We find there is a metal to topological insulator phase transition upon the application of pressure.