Deroughening of a 1D domain wall in an ultrathin magnetic film by a correlated defect

The interaction of a field-driven magnetic domain wall with a correlated defect was examined by Kerr imaging in subnanometer thin cobalt films. The wall was confined near the bottom of the effective potential trough by the line defect. A kinetic deroughening at a roughness exponent value of 0.1 which was below the characteristic roughness exponent value of random defects was observed. The restoring action of the effective potential trough explained the occurrence of deroughening on lengths greater than an inherent elastic screening length.