Tunneling of vortices through a weak link in an insulating Josephson array- art. no. 104501

A Josephson array ring in the insulating phase with circulating vortices is considered. The persistent vortex current is calculated as a function of t he charge at the center of the ring and the temperature, for the case of ne gligible dissipation. A weak link is introduced in the ring and the tunneli ng of vortices through it is described with the "dual Josephson equations." The Hamiltonian that describes the interaction of these devices with elect romagnetic fields is quantized. The use of such nonlinear devices as amplif iers and frequency converters of nonclassical microwaves is discussed.