Theory of current-induced torque in uniform ferromagnets

In a model ferromagnetic semiconductor (Ga,Mn)As with strong spin-orbit interaction, it has been experimentally shown that magnetization can be manipulated by injection of unpolarized currents [Chernyshov et al., Nat. Phys. 5, 656 (2009)]. We critically review the existing theoretical approaches to this phenomenon and present a model whose results are compared to more recent measurements of the current-induced torque driven by ferromagnetic resonance in (Ga,Mn)As. The results entail the dependence of the effect on carrier concentration, various types of strain, and temperature.