  The static conductivity of the dilute magnetic semiconductor GaMnAs is
calculated using the memory function formalism and time-dependent
density-functional theory to account for impurity scattering and to treat
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.
