Pressure tuning domain-wall chirality in noncentrosymmetric magnetic Weyl semimetal CeAlGe

TL;DR

This study investigates how hydrostatic pressure influences magnetic and topological properties of CeAlGe, revealing pressure-induced control over chiral domain walls and electromagnetic responses in a magnetic Weyl semimetal.

Contribution

It demonstrates pressure tuning of magnetic domain wall chirality and topological Hall effects in CeAlGe, highlighting magnetoelastic coupling as a control mechanism.

Findings

Pressure enhances antiferromagnetic exchange in CeAlGe.

Large topological Hall effect observed, splitting under pressure.

Electromagnetic response can be switched on/off via pressure.

Abstract

Topological magnetic Weyl semimetals have been proposed to host controllable chiral domain walls which bear a great prospect in device applications. To exploit them in applications, it is important to have a proper way to tune and manipulate these domain walls. One possible means is through magnetoelastic coupling. The involvement of rare earth in the lately proposed $R$Al$X$ ($R$=rare earth, $X$=Si and Ge) family magnetic Weyl semimetals may provide such a platform. Here we present transport and thermodynamic properties of CeAlGe under hydrostatic pressure. We find that pressure enhances the antiferromagnetic exchange in CeAlGe but essentially retains its magnetic structure. Large topological Hall effect with pronounced loop shape is observed within the magnetically ordered state, and it splits into two regions under pressure. Such an unusual electromagnetic response is inferred to be a consequence of chiral magnetic domain walls. The unprecedented concomitance of its evolution under pressure and the reentrance of antiferromagnetic order strongly suggest the capability of switching on/off this electromagnetic response in noncentrosymmetric magnetic Weyl semimetals via magnetoelastic coupling.