Transversal walls versus vortex walls in magnetic nanowires

In numeric simulations of magnetic nanowires several groups have observed two different types of reversal modes. It is suggested that the reversal mode corresponds to an energetically optimal domain wall profile. We investigate the energy minimisation problem in different regimes of thickness. When the radius goes to zero, the energy minimisation problem Γ-converges to a reduced local one dimensional problem. Thus for small radii, minimisers of the energy functional are almost constant on the cross section. This is not the case for big radii. For radius to infinity, a class of magnetisations with a vortex has the optimal energy scaling. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)