Domain wall dynamics in annealed GaMnAs epilayers

A. Dourlat (1) , V. Jeudy (1) , L. Thevenard (1) , A. Lemaitre (2) , C. Gourdon (1)

1 INSP - Institut des Nanosciences de Paris
2 LPN - Laboratoire de photonique et de nanostructures

We study magnetic field-driven domain wall motion in a GaMnAs thin film. The velocity is measured as function of the applied field. It varies over 6 orders of magnitude in a field range of 2.5 mT. Two regimes are identified. At low field, the domain wall motion follows a creep regime: it is controlled by defects and the domain wall velocity increases exponentially with the applied field. At higher fields, the domain wall motion follows a depinning regime: pinning defects are less efficient and the wall velocity increases linearly with the field. The highest measured domain wall velocity is 14 ms(-1).

Mots clés: domain wall; GaMnAs; magnetic semiconductor; pinning

Domaines: Matière Condensée [cond-mat]

A. Dourlat, V. Jeudy, L. Thevenard, A. Lemaitre, C. Gourdon. Domain wall dynamics in annealed GaMnAs epilayers. Journal of Superconductivity and Novel Magnetism, 2007, 20 (6), pp.453-455. ⟨10.1007/s10948-007-0247-2⟩. ⟨hal-01284379⟩