Nonlinear Piezomagnetic Effects in $g$-wave Altermagnets

TL;DR

This paper theoretically demonstrates that $g$-wave altermagnets exhibit a nonlinear piezomagnetic effect, where static strain induces net magnetization, providing a new way to characterize their physical properties.

Contribution

It introduces the concept of nonlinear piezomagnetic effects in $g$-wave altermagnets and compares it with $d$-wave altermagnets, highlighting the enhancement near large spin splitting.

Findings

Net magnetization is induced by second-order strain in $g$-wave altermagnets.

The induced magnetization is comparable to that in $d$-wave altermagnets.

Magnitudes of induced magnetization are enhanced when the Fermi level is on bands with large spin splitting.

Abstract

We theoretically study the generation of net magnetization induced by static strain in $g$-wave altermagnets, which exhibit the symmetric spin-split band structure under collinear spin textures free from the relativistic spin-orbit coupling. By analyzing a tight-binding model in a two-dimensional tetragonal system, we show that the $g$-wave altermagnets give rise to the nonlinear piezomagnetic effect, where a net magnetization is induced by the second-order strain. We compare the results for the $g$-wave altermagnets with those for the $d$-wave altermagnets, where the linear piezomagnetic effect occurs. As a result, we find that the induced magnetization is enhanced when the Fermi level lies on the band with the large spin splitting in both cases. We also show that the magnitudes of the induced magnetization are comparable to each other. Our results indicate that the nonlinear piezomagnetic effect is a good phenomenon to characterize the physical properties in $g$-wave altermagnets.