Superfluidity in Thin Films of 4He

This article reviews, from a very personal point of view, the origins and the early work on the superfluid to normal transition in very thin films of He-4 driven by vortex topological defects using a very crude description of the system which contains only the important physics. I cover the early papers with David Thouless and describe the important insights but also the errors and oversights since corrected by other workers. I then describe some of the all important experimental verifications of the smoking gun prediction of the universal discontinuity of the superfluid density at T=T-c and the necessary extensions to describe the dynamics necessary to compare with experiment.