Magnetic spin excitations in Mn doped GaAs : A model study

TL;DR

This paper presents a theoretical model study of magnetic spin excitations in Mn-doped GaAs, accurately reproducing experimental and ab-initio results, and providing insights into magnon states and their localization.

Contribution

The study introduces a generalized model that accurately predicts magnetic properties of Mn-doped GaAs, bridging first-principles calculations and model-based approaches.

Findings

Spin stiffness matches ab-initio results.

Good agreement with experimental data.

Identified mobility edge separating localized and extended magnon states.

Abstract

We provide a quantitative theoretical model study of the dynamical magnetic properties of optimally annealed Ga$_{1-x}$Mn$_x$As. This model has already been shown to reproduce accurately the Curie temperatures for Ga$_{1-x}$Mn$_x$As. Here we show that the calculated spin stiffness are in excellent agreement with those which were obtained from ab-initio based studies. In addition, an overall good agreement is also found with available experimental data. We have also evaluated the magnon density of states and the typical density of states from which the "mobility edge", separating the extended from localized magnon states, was determined. The power of the model lies in its ability to be generalized for a broad class of diluted magnetic semiconductor materials, thus it bridges the gap between first principle calculations and model based studies.