Nonlocal effects on magnetism in the diluted magnetic semiconductor Ga_{1-x}Mn_{x}As

TL;DR

This paper investigates the magnetic properties of Ga_{1-x}Mn_{x}As using a dynamical cluster approximation, emphasizing the importance of nonlocal effects, spin-orbit coupling, and strain in explaining experimental observations.

Contribution

It introduces a detailed theoretical model incorporating nonlocal effects, spin-orbit coupling, and strain to better understand magnetism in Ga_{1-x}Mn_{x}As.

Findings

Nonlocal effects are crucial for explaining transition temperature and saturation magnetization.

Strong cluster anisotropy causes rotational frustration and magnetic anisotropy.

Temperature-driven spin reorientation is explained by the model.

Abstract

The magnetic properties of the diluted magnetic semiconductor Ga_{1-x}Mn_{x}As are studied within the dynamical cluster approximation. We use the k-dot-p Hamiltonian to describe the electronic structure of GaAs with spin-orbit coupling and strain effects. We show that nonlocal effects are essential for explaining the experimentally observed transition temperature and saturation magnetization. We also demonstrate that the cluster anisotropy is very strong and induces rotational frustration and a cube-edge direction magnetic anisotropy at low temperature. With this, we explain the temperature-driven spin reorientation in this system.