  Spin-charge interconversion is currently the focus of intensive experimental
and theoretical research both for its intrinsic interest and for its potential
exploitation in the realization of new spintronic functionalities. Spin-orbit
coupling is one of the key microscopic mechanisms to couple charge currents and
spin polarizations. The Rashba spin-orbit coupling in a two-dimensional
electron gas has been shown to give rise to the inverse spin galvanic effect,
i.e. the generation of a non-equilibrium spin polarization by a charge current.
Whereas the Rashba model may be applied to the interpretation of experimental
results in many cases, in general in a given real physical system spin-orbit
coupling also occurs due other mechanisms such as Dresselhaus bulk inversion
asymmetry and scattering from impurities. In this work we consider the inverse
spin galvanic effect in the presence of Rashba, Dresselhaus and impurity
spin-orbit scattering. We find that the size and form of the inverse spin
galvanic effect is greatly modified by the presence of the various sources of
spin-orbit coupling. Indeed, spin-orbit coupling affects the spin relaxation
time by adding the Elliott-Yafet mechanism to the Dyakonov-Perel and,
furthermore, it changes the non-equilibrium value of the current-induced spin
polarization by introducing a new spin generation torque. We use a diagrammatic
Kubo formula approach to evaluate the spin polarization-charge current response
function. We finally comment about the relevance of our results for the
interpretation of experimental results.
