EFFECT OF THE EXCHANGE INTERACTION ON THE JOSEPHSON CURRENT AND THE ENERGY-SPECTRUM OF A SUPERCONDUCTING JUNCTION WITH A PARAMAGNETIC TUNNEL BARRIER

Within the framework of a microscopic theory, we show that paramagneti c moments contained in a dielectric layer between two superconductors induce destruction of Cooper pairs in the processes of tunneling and r eflecton from the interfaces with a spin flip. As a consequence, the d e Josephson critical current is reduced, and quasiparticle excitations of a new type with energies less than the superconducting gap appear. These excitations are characterized by strong damping due to scatteri ng which arises from the breaking of translational invariance in the p lane of the interface. The results of this study can be used to interp ret tunneling experiments on a Pb/Er(OH)3/Pb structure