Domain Wall Resistance in Perpendicular (Ga,Mn)As: dependence on pinning

TL;DR

This study examines how different pinning sites affect domain wall resistance in perpendicular (Ga,Mn)As, revealing that pinning type significantly influences spin transport properties.

Contribution

It demonstrates that the nature of pinning sites markedly impacts the intrinsic domain wall resistance in (Ga,Mn)As, highlighting the importance of pinning mechanisms.

Findings

Higher intrinsic DWR at etching step pinning

Lower intrinsic DWR at pinning lines in unetched material

Pinning type strongly influences spin transport across domain walls

Abstract

We have investigated the domain wall resistance for two types of domain walls in a (Ga,Mn)As Hall bar with perpendicular magnetization. A sizeable positive intrinsic DWR is inferred for domain walls that are pinned at an etching step, which is quite consistent with earlier observations. However, much lower intrinsic domain wall resistance is obtained when domain walls are formed by pinning lines in unetched material. This indicates that the spin transport across a domain wall is strongly influenced by the nature of the pinning.