Resonant impurity states in chemically disordered half-Heusler Dirac semimetals

Chadova, K.; Ködderitzsch, D.; Minár, J.; Ebert, H.; Kiss, J.; D'Souza, S. W.; Wollmann, L.; Felser, C. and Chadov, S. (2016): Resonant impurity states in chemically disordered half-Heusler Dirac semimetals. In: Physical Review B, Vol. 93, No. 19, 195102

Abstract

We address the electron transport characteristics in bulk half-Heusler alloys with their compositions tuned to the borderline between topologically nontrivial semimetallic and trivial semiconducting phases. Accurate first-principles calculations based on the coherent potential approximation (CPA) reveal that all the studied systems exhibit sets of dispersionless impurity-like resonant levels, with one of them being located at the Dirac point. By means of the Kubo-Bastin formalism we reveal that the residual conductivity of these alloys is strongly suppressed by impurity scattering, whereas the spin Hall conductivity exhibits a rather complex behavior induced by the resonant states. In particular for LaPt0.5Pd0.5Bi we find that the total spin Hall conductivity is strongly suppressed by two large and opposite contributions: the negative Fermi-surface contribution produced by the resonant impurity and the positive Fermi-sea term stemming from the occupied states. At the same time, we identify no conductivity contributions from the conical states.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 2469-9950
• Language: English