  In these lecture notes we study the disordered two-dimensional electron gas
in the presence of Rashba spin-orbit coupling, by using the Keldysh
non-equilibrium Green function technique. We describe the effects of the
spin-orbit coupling in terms of a SU(2) gauge field and derive a generalized
Boltzmann equation for the charge and spin distribution functions. We then
apply the formalism to discuss the spin Hall and the inverse spin galvanic
(Edelstein) effects. Successively we show how to include, within the
generalized Boltzmann equation, the side jump, the skew scattering and the spin
current swapping processes originating from the extrinsic spin-orbit coupling
due to impurity scattering.
