Magneto-Acoustic Waves in antiferromagnetic CuMnAs excited by Surface Acoustic Waves

TL;DR

This study demonstrates how surface acoustic waves induce magnetoelastic Nel vector waves in antiferromagnetic CuMnAs, revealing strain-driven spin dynamics without domain wall motion, with temperature-dependent effects.

Contribution

It presents the first observation of surface acoustic wave-induced Nel vector waves in CuMnAs, highlighting magnetoelastic coupling in antiferromagnets.

Findings

Surface acoustic waves induce Nel vector waves with micrometer wavelength.

The spin-axis rotation reaches up to 2.4 degrees due to strain.

Wave amplitude decreases at lower temperatures.

Abstract

Magnetoelastic effects in antiferromagnetic CuMnAs are investigated by applying dynamic strain in the 0.01% range through surface acoustic waves in the GaAs substrate. The magnetic state of the CuMnAs/GaAs is characterized by a multitude of submicron-sized domains which we image by x-ray magnetic linear dichroism combined with photoemission electron microscopy. Within the explored strain range, CuMnAs shows magnetoelastic effects in the form of N\'eel vector waves with micrometer wavelength, which corresponds to an averaged overall spin-axis rotation up to 2.4 deg driven by the time-dependent strain from the surface acoustic wave. Measurements at different temperatures indicate a reduction of the wave amplitude when lowering the temperature. However, no domain wall motion has been detected on the nanosecond timescale