Complex domain wall dynamics in compressively strained GaMnAs epilayers

TL;DR

This study investigates the complex behavior of domain walls in GaMnAs epilayers under strain, revealing different reversal mechanisms and suggesting potential for single domain device applications.

Contribution

It provides new insights into the dynamic behavior of domain walls influenced by uniaxial anisotropy in strained GaMnAs, with model estimates of nucleation and propagation energies.

Findings

(90+Delta) reversal is propagation dominated

(90-Delta) reversal involves multiple domain wall nucleation

Single domain devices are feasible using (90+Delta) mode

Abstract

The domain wall induced reversal dynamics in compressively strained GaMnAs was studied employing the magneto-optical Kerr effect and Kerr microscopy. Due to the influence of an uniaxial part in the in-plane magnetic anisotropy (90+/-Delta) domain walls with considerably different dynamic behavior are observed. While the (90+Delta) reversal is identified to be propagation dominated with a small number of domain walls, the case of (90-Delta) reversal includes the nucleation of many domain walls. The domain wall nucleation/propagation energy for both transitions are estimated using model calculations from which we conclude that single domain devices can be achievable using the (90+Delta) mode.