Fluctuations in a Josephson Junction

Abstract
The classical-field description of a long Josephson junction is reinterpreted as a quantum-field theory, which allows a unified treatment of fluctuation phenomena in both the Meissner state and the mixed state. For practical configurations, the mean square fluctuations in the field ϕ are negligible, and the zero-point corrections to the energy in the mixed state are less than 1%.