Universal dimensional crossover of domain wall dynamics in ferromagnetic films

W. Savero Torres, R. Diaz Pardo, S. Bustingorry, A. B. Kolton, A. Lemaître, V. Jeudy

Published 2018-11-26Version 1

The magnetic domain wall motion driven by a magnetic field is studied in (Ga,Mn)As and (Ga,Mn)(As,P) films of different thicknesses. In the thermally activated creep regime, a kink in the velocity curves and a jump of the roughness exponent evidence a dimensional crossover in the domain wall dynamics. The measured values of the roughness exponent zeta_{1d} = 0.62 +/- 0.02 and zeta_{2d} = 0.45 +/- 0.04 are compatible with theoretical predictions for the motion of elastic line (d = 1) and surface (d = 2) in two and three dimensional media, respectively.