Tunable band inversion in half-Heusler topological LuAuSn/LuPtBi superlattices

A heterostructure formed of topological and nontopological half-Heusler compounds provides a means to tune band inversion. In this work, we study the stabilities of [111] and [100] LuPtBi/LuAuSn half-Heusler superlattices. Since the [111] superlattice is more stable than the [100] one, we explore the band inversion in the [111] superlattice. By increasing the number of LuPtBi layers, the energy gap can be tuned from 0.63 to −1.50 eV, where the negative value indicates band inversion. The underlying mechanism involves band alignment, internal electric field, and quantum confinement. Our study offers an efficient means to obtain the desired band inversion in half-Heusler heterostructures.