First-principles study of electronic structure and Fermi surface in semimetallic YAs

Abstract

In the course of searching for new systems, which exhibit nonsaturating and extremely large positive magnetoresistance, electronic structure, Fermi surface, and de Haas-van Alphen characteristics of the semimetallic YAs compound were studied using the all-electron full-potential linearized augmented-plane wave (FP-LAPW) approach in the framework of the generalized gradient approximation (GGA). In the scalar-relativistic calculation, the cubic symmetry splits fivefold degenerate Y-d orbital into low-energy threefold-degenerate t(2g) and twofold degenerate doublet e(1g) states at Gamma point around the Fermi energy. One of them, together with the threefold degenerate t(1u) character of Asp orbital, render the YAs semimetal with a topologically trivial band order and fairly low density of states at the Fermi level. Including spin-orbit (SO) coupling into the calculation leads to pronounced splitting of the t(1u) state and shifting the bands in the energy scale. Consequently, the determined four different 3-dimensional Fermi surface sheets of YAs consists of three concentric hole-like bands at G and one ellipsoidal electron-like sheet centred at the X points. In full accordance with the previous first-principles calculations for isostructural YSb and YBi, the calculated Fermi surface of YAs originates from fairly compensated multi-band electronic structures.