First-principles investigation of magnetic and transport properties in hole-doped shandite compounds Co$_3$In$_x$Sn$_{2-x}$S$_2$

TL;DR

This study uses first-principles calculations to explore how hole doping with indium affects the magnetic and transport properties of Co$_3$Sn$_2$S$_2$, revealing significant changes in anomalous Hall and Nernst effects.

Contribution

It provides a detailed theoretical analysis of doping effects on magnetic Weyl semimetals, highlighting band structure changes and transport phenomena.

Findings

Nonlinear reduction of anomalous Hall conductivity with In doping

Reversal of anomalous Nernst conductivity sign due to band parity changes

Correlation between band structure evolution and transport properties

Abstract

Co-based shandite Co$_3$Sn$_2$S$_2$ is a representative example of magnetic Weyl semimetals showing rich transport phenomena. We thoroughly investigate magnetic and transport properties of hole-doped shandites Co$_3$In$_x$Sn$_{2-x}$S$_2$ by first-principles calculations. The calculations reproduce nonlinear reduction of anomalous Hall conductivity with doping In for Co$_3$Sn$_2$S$_2$, as reported in experiments, against the linearly decreased ferromagnetic moment within virtual crystal approximation. We show that a drastic change in the band parity character of Fermi surfaces, attributed to the nodal rings lifted energetically with In-doping, leads to strong enhancement of anomalous Nernst conductivity with reversing its sign in Co$_3$In$_x$Sn$_{2-x}$S$_2$.