Influence of tetragonal distortion on the topological electronic structure of the half-Heusler compound LaPtBi from first principles

TL;DR

This study uses first-principles calculations to show how tetragonal distortion and strain can tune the electronic and topological properties of LaPtBi, potentially enabling strain-engineered topological insulators.

Contribution

It demonstrates how in-plane strain affects the band structure and induces a sizable bulk band gap in LaPtBi, guiding the realization of topological insulators in half-Heusler compounds.

Findings

Band structures and Fermi level are tunable by strain.

A 0.3 eV bulk band gap can be induced with compressive strain.

Strain engineering can realize topological insulators in LaPtBi.

Abstract

The electronic structures of tetragonally distorted half-Heuselr compound LaPtBi in the C1b structure are investigated in the framework of density functional theory using the full potential linearized augmented plane with local spin density approximation method. The calculation results show that both the band structures and the Fermi level can be tuned by using either compressive or tensile in-plane strain. A large bulk band gap of 0.3 eV can be induced through the application of a compressive in-pane strain in LaPtBi with the assumption of a relaxed volume of the unit cell. Our results could serve as a guidance to realize topological insulators in half-Heusler compounds by strain engineering.