Applying the formalism of action-angle variables in quantum statistics to an exactly solvable model Hamiltonian, explicit expressions have been calculated relating the superfluid tunneling current and the corresponding phase coupling between two helium baths connected by an orifice. The relevance of the calculation to a recent experiment has been pointed out.

• Received 3 March 1970

DOI:https://doi.org/10.1103/PhysRevA.2.2568