Pinning a Domain Wall in (Ga,Mn)As with Focused Ion Beam Lithography

TL;DR

This paper demonstrates how focused ion beam lithography can create and manipulate domain wall pinning sites in (Ga,Mn)As, enabling precise control of magnetic domain walls for potential spintronic applications.

Contribution

It introduces a novel method using focused Ga+ ion beams to define and manipulate domain wall pinning sites in (Ga,Mn)As, advancing magnetic control techniques.

Findings

Focused ion beams create local anisotropy sites.

Domain walls can be manipulated at these sites.

An upper limit on local anisotropy energy is established.

Abstract

We utilize a focused beam of Ga+ ions to define magnetization pinning sites in a ferromagnetic epilayer of (Ga,Mn)As. The nonmagnetic defects locally increase the magneto-crystalline anisotropy energies, by which a domain wall is pinned at a given position. We demonstrate techniques for manipulating domain walls at these pinning sites as probed with the giant planar Hall effect (GPHE). By varying the magnetic field angle relative to the crystal axes, an upper limit is placed on the local effective anisotropy energy.