Magnetoelastic properties in the high-temperature magnetic phase of the skyrmion compound GdRu$_2$Si$_2$

TL;DR

This study explores the magnetoelastic behavior of GdRu$_2$Si$_2$ under magnetic fields, revealing anomalies linked to its complex phase diagram and proposing models to explain the elastic responses of its high-temperature magnetic phase.

Contribution

It provides new insights into the magnetoelastic properties of GdRu$_2$Si$_2$, especially regarding its high-temperature magnetic phase and introduces models to explain observed elastic anomalies.

Findings

Strong sound velocity anomalies linked to magnetic phases.

High-temperature phase stability depends on magnetic field direction.

Qualitative agreement between models and experimental anomalies.

Abstract

We investigated the magnetoelastic properties of a GdRu$_2$Si$_2$ single crystal under a magnetic field applied along the crystallographic [001] and [110] directions. We report a series of strong anomalies in the sound velocity that is consistent with the complex phase diagram reported previously for this compound. In particular, in our study we focus on the recently identified magnetic phase in the high-temperature region. We show that while this phase is easily destroyed for magnetic fields applied along [001], it is rather stable for fields along [110]. Furthermore, we introduce a Landau theory and a microscopic toy model describing the elastic response at zero field. We reproduce qualitatively the observed anomalies for different acoustic modes, which allows us to propose a magnetic structure for this new high-temperature phase.