On the nature of ferromagnetism in diluted magnetic semiconductors: GaAs:Mn, GaP:Mn

TL;DR

This paper develops a microscopic model for ferromagnetism in diluted magnetic semiconductors, showing how mobile holes induce magnetic ordering, with predictions aligning with experimental data for GaAs:Mn and GaP:Mn.

Contribution

It introduces a microscopic Hamiltonian capturing the exchange mechanism in DMS, linking the Zener-like interaction to experimental Curie temperatures.

Findings

The model explains ferromagnetism in GaAs:Mn and GaP:Mn.

Estimated Curie temperatures match experimental results.

The exchange mechanism resembles the Zener model in transition metal oxides.

Abstract

A microscopic Hamiltonian for interacting manganese impurities in diluted magnetic semiconductors (DMS) is derived. It is shown that in p -type III-V DMS the indirect exchange between Mn impurities has similarities with the Zener mechanism in transition metal oxides. Here the mobile holes and localized states near the top of the valence band play the role of unoccupied oxygen orbitals which induce ferromagnetism. The Curie temperature estimated from the proposed kinematic exchange agrees with recent experiments on GaAs:Mn. The model is also applicable to the GaP:Mn system.