Nonequilibrium phenomena in nonsymmetrical superconducting double-barrier structure Nb/NbOx/Al/AlOx/Nb

Tunneling structure Nb/NbOx/Al/AlOx/Nb with thin barrier in the Nb/NbOx/Al junction and 4-6 nm thick Al interlayer was prepared and experimentally studied. Pair breaking at the tunneling processes in one junction produces nonequilibrium state of quasiparticle density in Al interlayer and consequently nonequilibrium tunneling processes in the whole structure. All joined effects, namely gap voltage suppression, presence of negative differential resistance at gap voltage and effects induced by applying of microwave radiation are similar to those observed on stacked Nb/Al/AlOx/Nb tunnel junction current-voltage characteristics. Results may be used for the interpretation of behavior of high current density, SNS or SIS type multilayers of low and high temperature superconductor structures.