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 alphaw and the effective out-of-plane spin-transfer torque parameter betaw are dominated by spin-orbit interaction in combination with scattering off the domain wall, and not scattering off extrinsic impurities. Numerical calculations give alphaw approximately 0.01 and betaw approximately 1 in dirty (Ga,Mn)As. The extraordinarily large betaw parameter allows experimental detection of current or voltage induced by domain wall motion in (Ga,Mn)As.
Hals
Kjetil Magne Dørheim
KM
Department of Physics, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway.
Nguyen
Anh Kiet
AK
Brataas
Arne
A