Modeling of dI/dV-characteristics of weakly coupled superconductors of Josephson type in tunnel regime

Abstract

With the scattering matrix method in the work were modeled current-voltage, dI/dV -, d²I dV²  - characteristics of weakly coupled superconductors of Josephson type in tunnel regime. At the calculation of the transport characteristics the relative transparency of the transition barrier ranged from 0,059 to 10-4. It is shown that with a decrease in the transparency of the barrier (with increasing of barrier height) the main contribution to the current brings tunneling Cooper pairs of electrons (tunnel regime). On the current-voltage and dI(V)/dV -characteristics of the superconducting junction in tunnel regime there is a sharp increase in the quasiparticle current at gap voltages V_g1, V_g2 ,  and the values of the bias voltage maxima correspond to the differential conductivity. These changes are observed on the d²I/dV²-characteristics. The modeling results are in good agreement with the experimental data. The results may be useful for calculating the elements of superconducting electronics.