Boltzmann theory of engineered anisotropic magnetoresistance in (Ga,Mn)As

TL;DR

This paper presents a theoretical analysis of anisotropic magnetoresistance in (Ga,Mn)As, showing how strain and composition can control resistance differences related to magnetization orientation.

Contribution

It introduces a Boltzmann transport model that incorporates scattering from ionized acceptors and defects, predicting tunable anisotropic magnetoresistance in (Ga,Mn)As.

Findings

Resistivity differences depend on magnetization direction and can be predicted by the model.

Strain engineering can reverse the sign of anisotropic magnetoresistance.

Chemical composition adjustments can modify the magnitude of anisotropic magnetoresistance.

Abstract

We report on a theoretical study of dc transport coefficients in (Ga,Mn)As diluted magnetic semiconductor ferromagnets that accounts for quasiparticle scattering from ionized Mn$^{2+}$ acceptors with a local moment $S=5/2$ and from non-magnetic compensating defects. In metallic samples Boltzmann transport theory with Golden rule scattering rates accounts for the principle trends of the measured difference between resistances for magnetizations parallel and perpendicular to the current. We predict that the sign and magnitude of the anisotropic magnetoresistance can be changed by strain engineering or by altering chemical composition.