Intrinsic Coupling between Current and Domain Wall Motion in (Ga,Mn)As

We consider current-induced domain wall motion and, the reciprocal process, moving domain wall-induced current. The associated Onsager coefficients are expressed in terms of scattering matrices. Uncommonly, in (Ga,Mn)As, the effective Gilbert damping coefficient ${\alpha }_w$ and the effective out-of-plane spin transfer torque parameter ${\beta }_w$ are dominated by spin-orbit interaction in combination with scattering off the domain wall, and not scattering off extrinsic impurities. Numerical calculations give $\alpha_w \sim 0.01$and$\beta_w \sim 1$indirty(Ga,Mn)As\mathrm{.}Theextraordinarylarge$\beta_w$ parameter allows experimental detection of current or voltage induced by domain wall motion in (Ga,Mn)As.