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/NbOx/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