Edge-domain wall controls the switching behaviour in ultra-thin films
and understanding them is of fundamental importance. The edge domains
in an anti-parallel coupled bilayer magnetic him can be well reproduce
d by the analytic exact two-solition solution of the imaginary time Si
ne-Gordon equation. For a single-layer film, the domain pattern deviat
es slightly from the two-soliton equation because of uncompensated mag
netic charges near the corners and at the domain walls. As the number
of the layers is increased and switches between even and odd, the doma
in pattern also switches between these two limits. The deviation from
the two soliton solution becomes smaller because the net uncompensated
magnetic charge per unit layer decreases. (C) 1998 Elsevier Science B
.V. All rights reserved.