Insulating Half‐Heusler TmPdSb with Unusual Band Order and Metallic Surface States.

Theoretical and experimental results exploring a half‐Heusler compound TmPdSb with unusual band order and metallic surface states are presented. Typically, the half‐Heusler systems exhibit topological features in a semimetallic state, and trivial ones in an insulating state. Topological properties of the most of half‐Heusler systems are related to the band inversion around the Fermi level, similar to this observed in CdTe/HgTe systems. In the case of TmPdSb, the gapped electronic band structure with "band inversion" in the conductance band is observed, while the slab‐like system realized metallic surface states. The bulk insulating nature of the compound is corroborated by means of electrical transport measurements. The experimental data reveal several features due to the presence of metallic surface states, such as linear magnetoresistance and weak‐antilocalization effect, characterized by enhanced coherence length and a very large number of surface conductive channels. The findings reveal new features of the rare‐earth bearing half‐Heusler. [ABSTRACT FROM AUTHOR]