Some Experiments with Superfluid 4He Films: From Persistent Currents to the Kosterlitz–Thouless Transition.

Presented here is a brief selective survey of some of the experiments with superfluid 4 He that helped to move forward our understanding of the ability of helium to support persistent flow, especially for helium films. In addition, we discuss some of the experiments that helped to solidify an understanding of the two-dimensional 4 He phase transition. The selectivity is based on some of the areas of helium film work in which the work of John Reppy and his group had contact and parallels with the work of my group. [ABSTRACT FROM AUTHOR]