Interlayer Exchange Coupling in (Ga,Mn)As-based Superlattices

TL;DR

This paper presents a theoretical study of interlayer exchange coupling in (Ga,Mn)As-based superlattices, explaining experimental results and predicting new antiferromagnetic coupling possibilities using a tight-binding model.

Contribution

It introduces a unified theoretical model that explains both ferromagnetic and antiferromagnetic interlayer couplings in semiconductor superlattices, extending understanding of magnetic interactions.

Findings

The model explains experimental interlayer coupling behaviors.

It predicts conditions for antiferromagnetic coupling in (Ga,Mn)As structures.

The mechanism is applicable across different superlattice materials.

Abstract

The interlayer coupling between (Ga,Mn)As ferromagnetic layers in all-semiconductor superlattices is studied theoretically within a tight-binding model, which takes into account the crystal, band and magnetic structure of the constituent superlattice components. It is shown that the mechanism originally introduced to describe the spin correlations in antiferromagnetic EuTe/PbTe superlattices, explains the experimental results observed in ferromagnetic semiconductor structures, i.e., both the antiferromagnetic coupling between ferromagnetic layers in IV-VI (EuS/PbS and EuS/YbSe) superlattices as well as the ferromagnetic interlayer coupling in III-V ((Ga,Mn)As/GaAs) multilayer structures. The model allows also to predict (Ga,Mn)As-based structures, in which an antiferromagnetic interlayer coupling could be expected.