d0-d half-Heusler compounds as a potential class of three-dimensional Chern insulators

The high-Tc three-dimensional (3D) Chern insulators are in much demand for the future spin-polarized, massless and dissipationless current applications. Employing ab initio electronic calculations, a novel class of stoichiometric d(0)-d Dirac and parabolic half-metals in half-Heusler C1(b) structure with a good chance of application as quantum anomalous Hall materials is proposed including half-Heusler KMnP, KMnSb, RbMnP, RbMnSb, KMnN, and RbMnN. The robust gamma(1)-gamma(5) band inversion across the Fermi level in the semi-metallic spin channel, which results from the s-d hybridization of Mn states together with the maximum d-shell exchange splitting, gives rise to a non-trivial topology with a Chern number C = 1 in all the above compounds. With the intrinsic spin-orbit coupling included, a small gap appears in the semi-metallic spin channel that can be further magnified via uniaxial strain, thus converting the above compounds to genuine 3D Chern insulators. The above theoretical findings in d(0)-d half-Heusler structures together with the characteristic high Curie temperatures and dynamical stability, open an intriguing pathway to realization of quantum anomalous Hall effect in stoichiometric 3D materials.