Large anomalous Hall conductivity in Weyl ferrimagnet Cs2Co3 S4 predicted by density-functional calculations

Abstract

The identification of topological Weyl semimetals has recently gained considerable attention. Here, we report the results of density-functional theory calculations regarding the magnetic properties, the electronic structure, and the intrinsic anomalous Hall conductivity of the title compound, which was synthesized already 50 years ago but received little attention until now. We found Cs2Co3S4 to be a ferrimagnetic half-metal with a total spin magnetic moment of about 3μB per formula unit. It shows an energy band gap of 0.36 eV in the majority-spin channel and a pseudogap at the Fermi level in the minority-spin channel. We identified several sets of low-energy Weyl points and traced their dependence on the direction of magnetization. The intrinsic anomalous Hall conductivity is predicted to reach a magnitude of up to 500 ω-1cm-1, which is comparable to values obtained in other celebrated Weyl semimetals.