JOURNAL OF HIGH ENERGY PHYSICS, sa.8, 2001 (SCI-Expanded)
We study the finite temperature phase transition in 2+1 dimensional compact QED and its dual theory: Josephson junction. Duality of these theories at zero temperature was established long time ago in [1]. Phase transition in compact QED is well studied thus we employ the 'duality' to study the superconductivity phase transition in a Josephson junction. For a thick junction we obtain a critical temperature in terms of the geometrical properties of the junction.