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

Abstract

The electronic structures of tetragonally distorted half-Heuselr compound LaPtBi in the C1 b 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. ___________ a) Electronic

Large Linear Magnetoresistance and Shubnikov-de Hass Oscillations in Single Crystals of YPdBi Heusler Topological Insulators

“…The recent discoveries of giant linear MR in Bi 2 Se 3 1011 and Bi 2 Te 3 1213 topological insulators (TIs) has brought renewed interest to linear MR. Because of their unusual surface states that are naturally zero bandgap with linear dispersion, TIs provide a perfect platform on which to study the origin of linear MR. Because some Heusler compounds have recently been predicted to be TIs141516, it is worth investigating whether large linear MR can also be observed in Heusler alloys. Considerable efforts have been devoted to the study of the electric structures and transport properties of a number of Heusler-based TIs171819202122232425. X-ray photoelectron spectroscopy results have shown that such Heusler-based materials as YPtSb, LaPtBi, LuPtSb and LuPdBi are gapless semiconductors with very high mobility212224 although large linear MR and desired Shubnikov-de Haas (SdH) quantum oscillations have not been observed experimentally in these materials.…”

Three-dimensional topological insulators: case of quaternary Heusler compounds

“…Similar to the half-Heusler compounds [18], these quaternary Heusler compounds with topologically insulating property cannot have a non-zero band gap at C point at the Fermi level because of the cubic symmetry. The cubic symmetry protects the degeneration of C 8 states not to be destroyed.…”

“…The earlier reports showed that the inverse Heusler structure can be considered as two hybridized interpenetrating zinc-blendes, which are X-X and M-Z [18]. Quaternary Heusler compounds have the chemical formula of XX'MZ, where X, X', and M are different transition metals, and Z is a main group element.…”

“…In 2007, the three-dimensional (3D) topological insulators were proposed theoretically [7]. Up to now, the 3D topological insulators have been discovered in several kinds of material systems, such as tetradymite Bi 2 Se 3 and Bi 2 Te 3 , half-Heusler LaPtBi, chalcopyrite AuTlTe 2 , layered honeycomb lattice Na 2 IrO 3 , and also the perovskite YBiO 3 [9][10][11][12][13][14][15][16][17][18][19]. At present, the search for topological insulators is extended to the inverse Heusler compounds [20,21].…”

“…The important reflection of topological insulators in electronic structure is to exhibit an inverted band structure [18,19]. The search for topological insulators greatly benefits from the topological band theory.…”