Temperature-dependent resistivity of ferromagnetic Ga1‑xMnxAs : Interplay between impurity scattering and many-body effects

Abstract

The static conductivity of the diluted magnetic semiconductor Ga1−xMnxAs is calculated using an equation of motion approach for the current response combined with time-dependent density-functional theory to account for Hartree and exchange interactions within the hole gas. We find that the Coulomb scattering off the charged impurities alone is not sufficient to explain the experimentally observed drop in resistivity below the ferromagnetic transition temperature: the often overlooked scattering off the fluctuations of localized spins is shown to play a significant role.