  We study spin-orbit torques (SOT) in non-degenerate multiband electron
systems in the weak disorder limit. In order to have better physical
transparency a semiclassical Boltzmann approach equivalent to the Kubo
diagrammatic approach in the non-crossing approximation is formulated. This
semiclassical framework accounts for the interband- coherence effects induced
by both the electric field and static impurity scattering. Using the
two-dimensional Rashba ferromagnet as a model system, we show that the
antidamping-like SOT arising from disorder-induced interband-coherence effects
is very sensitive to the spin structure of disorder and may have the same sign
as the intrinsic SOT in the presence of spin-dependent disorder. While the
cancellation of this SOT and the intrinsic one occurs only in the case of
spin-independent short-range disorder.
