Fluxons in dual thin films

The field and current distribution for a fluxon penetrating two thin parallel films is obtained. This result is used to calculate the coupling force for an isolated fluxon extending through the two films. The calculation is valid for arbitrary separation between the films when d₁≪λ₁, d₂≪λ₂, and the fluxon core radii are much less than λ. Here d₁ and d₂ are the film thicknesses and λ₁ and λ₂ are the penetration depths. The conditions of validity of a previous calculation for zero separation between the films are established and the comparison with recent experimental work is discussed.