Suppression of magnetism in Co$_3$Sn$_2$S$_2$ under external pressure

TL;DR

This study investigates how applying external pressure up to 10.8 GPa suppresses magnetism in Co$_3$Sn$_2$S$_2$, combining experimental measurements with refined theoretical models to understand the underlying mechanisms.

Contribution

The paper introduces a combined experimental and theoretical approach to accurately model pressure-induced suppression of magnetism in Co$_3$Sn$_2$S$_2$, addressing limitations of standard DFT calculations.

Findings

Magnetization decreases with increasing pressure.

Adjusting sulfur atom positions aligns theory with experiment.

Refined models reproduce experimental optical spectra.

Abstract

The ability to control the magnetic state provides a powerful means to tune the underlying band topology, enabling transitions between distinct electronic phases and the emergence of novel quantum phenomena. In this work, we address the evolution of ferromagnetic state upon applying external pressures up to 10.8~GPa using a combined experimental and theoretical study. The standard \emph{ab initio} Density Functional Theory computation including ionic relaxations grossly overestimates the unit cell magnetization as a function of pressure. In our theoretical analysis we identify two possible mechanisms to remedy this shortcoming. Matching the experimental observations is achieved by a symmetry-preserving adjustment of the sulfur atoms position within the unit cell. Alternatively, we explore various combinations of the exchange and correlation parts of the effective potential which reproduce the experimental magnetization, the structural parameters and the measured optical conductivity spectra. Thus, the pressure-dependent behavior of magnetization demands a careful theoretical treatment and analysis of theoretical and experimental data.