Domain-wall transformation by high-frequency magnetic fields

The high-frequency behavior of magnetic domain-walls of the cross-tie type is investigated by static and time-resolved Kerr microscopy. By applying a high-frequency (hf) sinusoidal in-plane magnetic field perpendicular to the wall plane, additional vortex-antivortex pairs are created that lead to a shrinking of the cross-tie spacing. This creation of additional Bloch lines happens by a channelized flux transport across the wall plane at the vortex sites until a new metastable narrow-spaced cross-tie state is reached.