Enhanced carrier scattering rates in dilute magnetic semiconductors with correlated impurities

TL;DR

This paper investigates how impurity correlations in dilute magnetic semiconductors influence carrier scattering, revealing that impurity clustering significantly enhances charge scattering rates, which can be tuned via annealing.

Contribution

It derives a general expression for the current relaxation kernel considering impurity correlations and demonstrates the impact of clustering on scattering rates in DMSs.

Findings

Impurity clustering enhances charge scattering in DMSs.

Scattering enhancement depends on cluster parameters.

Post-growth annealing can control impurity clustering.

Abstract

In III-V dilute magnetic semiconductors (DMSs) such as Ga$_{1-x}$Mn$_x$As, the impurity positions tend to be correlated, which can drastically affect the electronic transport properties of these materials. Within the memory function formalism we have derived a general expression for the current relaxation kernel in spin and charge disordered media and have calculated spin and charge scattering rates in the weak-disorder limit. Using a simple model for magnetic impurity clustering, we find a significant enhancement of the charge scattering. The enhancement is sensitive to cluster parameters and may be controllable through post-growth annealing.