ON MAGNETIC-FLUX DYNAMICS IN 1D ARRAYS OF UNDERDAMPED JOSEPHSON-JUNCTIONS

We have measured the current-voltage characteristics of parallel biased arrays of small Nb/NbO(x)/Pb Josephson junctions connected by superconducting loops. Depending on the temperature of the sample, the application of a magnetic field perpendicular to the planes of the loops gives rise to linear branches and flux-flow steps in the current-voltage characteristics of the arrays. For increasing temperatures the linear branches evolve in resonant flux-flow like singularities. Good agreement between the experimental data and the direct numerical simulations based on the discrete Josephson transmission line model is found.