Remarkable Topological Features of Electronic Band Dispersion of IrGa and RhGa Compounds from First Principles

Exotic behavior of linearly dispersed electronic bands near the Fermi level implies advanced physical properties in a material. In this paper, we present an ab initio study of the electronic properties of IrGa and RhGa, with and without spin-orbit interaction, using first-principles calculations. Linearly dispersed band crossings, reminiscent of topological semimetallic band structures, were identified near the Fermi energy. These include type-I and type-II Dirac points and nodal lines. By applying compressive and tensile stress to the lattice along x, y, and z, the response to the band structure near the Fermi level has been studied.