Metallic surface electronic state in half-Heusler compounds RPtBi (R = Lu, Dy, Gd)

TitleMetallic surface electronic state in half-Heusler compounds RPtBi (R = Lu, Dy, Gd)
Publication TypeJournal Article
Year of Publication2011
AuthorsLiu C, Lee Y, Kondo T, Mun ED, Caudle M, Harmon BN, Bud'ko SL, Canfield PC, Kaminski A
Journal TitlePhysical Review B
Date Published05
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000291005600002
Keywordsbi2te3, hgte quantum-wells, phase, ternary compounds, topological insulators, transition, TRANSPORT

Rare-earth platinum bismuth (RPtBi) has been proposed recently as a potential topological insulator. In this paper, we present measurements of the metallic surface electronic structure in three members of this family, using angle-resolved photoemission spectroscopy (ARPES). Our data show clear spin-orbit splitting of the surface bands and the Kramers' degeneracy of spins at the (Gamma) over bar and (M) over bar points, which is reproduced nicely with our full-potential linearized augmented plane wave calculation for a surface electronic state. Topologically nontrivial behavior is signified by band inversion in the calculated bulk electronic structures, yet no direct indication of such behavior is detected by ARPES except for a weak Fermi crossing detected in close proximity to the (Gamma) over bar point, making the total number of Fermi crossings odd. In the surface band calculation, however, this crossing is explained by a Kramers pair of bands that are very close to each other. The classification of this family of materials as topological insulators remains an open question.

URL<Go to ISI>://000291005600002
Alternate JournalPhys. Rev. B