FLOW IN THIN-FILMS OF SUPERFLUID HE-3 ON ROUGH SURFACES

The superflow of He-3 in thin films on rough surfaces is studied using the formalism of microscopic theory. The gap equation is solved and the free energy and the superflow are calculated for three two-dimensional states that may exist in films with thickness d approximately xi0. In the absence of flow the two-dimensional B state and the two-dimensional A state are degenerate and energetically more favourable than other two-dimensional states. In the presence of flow the two-dimensional A state has the lowest energy. For increasing superflow there occurs a transition from the two-dimensional A state to the two-dimensional polar state. The order of this transition depends on temperature and the strength of pair breaking on the surface. The theory is compared with recent experimental results.