Effect of residual strain on non-collinear antiferromagnetic structure in Weyl semimetal Mn3Sn

TL;DR

This study investigates how residual strain influences the magnetic structure of Mn3Sn, revealing that strain extends the temperature range of non-coplanar antiferromagnetic order and enables topological effects, advancing the engineering of topological antiferromagnets.

Contribution

It demonstrates that residual strain can stabilize non-coplanar AFM structures in Mn3Sn across a wider temperature range, offering a new method for engineering topological antiferromagnets.

Findings

Residual strain extends AFM order to 5 K from 285 K.

Anomalous and topological Hall effects appear with residual strain.

Strain engineering enables realization of chiral non-coplanar AFM structures.

Abstract

The non-collinear antiferromagnetic (AFM) structure makes Mn3Sn exhibit exotic properties. At present, it has been found that both the hydrostatic pressure and the strain introduced by interstitial N atoms have a great influence on this magnetic structure. Here, the effect of the residual strain (RS) on it is investigated. AC and DC magnetic measurement results suggest that Mn3Sn without RS has the non-collinear AFM structure only in the temperature range of 285 K to 400 K; while Mn3Sn with RS has a non-coplanar AFM structure in the entire temperature range from 5 K to 400 K. Both anomalous Hall effect and topological Hall effect appears in Mn3Sn with RS, supporting the anticipated non-coplanar AFM structure. Our findings point out a method to realize the chiral non-coplanar AFM structure through the engineering, thereby providing a path for the construction of topological antiferromagnets.