Phase oscillations in superfluid 3 He − B weak links

Oscillations in quantum phase about a mean value of π, observed across micropores connecting two 3He−B baths, are explained in a Ginzburg-Landau phenomenology. The dynamics arises from the Josephson phase relation,the interbath continuity equation, and helium boundary conditions. The pores are shown to act as Josephson tunnel junctions, and the dynamic variables are the inter bath phase difference and fractional difference in superfluid density at micropores. The system maps onto a non-rigid, momentum-shortened pendulum, with inverted-orientation oscillations about a vertical tilt angle φ = π, and other modes are predicted. PACS: 03.75Fi, 67.57.-z,74.50.+r Typeset using REVTEX