Observation of the superfluid Shapiro effect in a He-3 weak link - art. no. 035301

We have studied the mass currents through a superfluid He-3 Josephson weak link in the presence of an externally applied ac pressure modulation. Chara cteristic changes in the dc mass currents are observed whenever the superfl uid Josephson frequency omega (J) is an integer multiple of the ac modulati on frequency omega. The measured dependencies of these current changes on a c pressure amplitude are in excellent agreement with theory describing quan tum phase dynamics of superfluid He-3 weak links. These results establish t he superfluid analog of the superconducting Shapiro effect.