Large anomalous Hall conductivity in Weyl ferrimagnet Cs$_{2}$Co$_{3}$S$_4$ predicted by density-functional calculations

TL;DR

This study predicts that Cs$_{2}$Co$_{3}$S$_4$ is a ferrimagnetic Weyl semimetal with significant anomalous Hall conductivity, based on density-functional theory calculations, highlighting its potential for topological electronic applications.

Contribution

First prediction of Weyl semimetal behavior and large anomalous Hall conductivity in Cs$_{2}$Co$_{3}$S$_4$ using density-functional theory.

Findings

Cs$_{2}$Co$_{3}$S$_4$ is a ferrimagnetic half-metal with a 0.36 eV band gap.

Multiple low-energy Weyl points identified, dependent on magnetization direction.

Predicted anomalous Hall conductivity up to 500 Ω$^{-1}$cm$^{-1}$.

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, hitherto. We found Cs$_{2}$Co$_{3}$S$_4$ to be a ferrimagnetic half-metal with a total spin magnetic moment of about 3 $\mu_B$ per formula unit. It shows energy band gap of 0.36 eV in the majority-spin channel and a pseudo-gap 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 up to 500 $\Omega^{-1}$cm$^{-1}$, which is comparable to values obtained in other celebrated Weyl semimetals.