Spectrum and thermodynamic currents in one-dimensional Josephson elements

The de Josephson effect is considered from the thermodynamic point of view. Universal thermodynamic equations, relating both bound and continuum contr ibutions to the Josephson current with the normal electron scattering ampli tudes are derived for the single mode case. To derive these equations we us e and further develop the method of spatial separation between the supercon ducting and normal parts of the junction. We also use this method to find t he Andreev bound states in structures containing superconducting components . The general thermodynamic formulas are applied to the calculation of the current in various Josephson-type structures. In particular, the crucial ro le of the continuum contribution is demonstrated, even for short junctions (where it is usually neglected). We also find structures where the bound st ates supporting the giant currents are well separated; thus they can, hopef ully, be populated nonuniformly and such current can be measured.