Spatial inhomogeneity of the interaction between bistable ferromagnetic wires

An experimental study and a theoretical calculation are presented of the hysteresis loop of two bistable ferromagnetic wires. A new effect-an asymmetry of the shift of the switching field at the first and the second Barkhausen jump-is found experimentally. The effect is explained as a consequence of the spatial dependence of the stray field. It is also reproduced within our recent calculation of the stray field from the magnetisation profile. Theoretical results qualitatively agree with the experimental data.