Flux flow in current driven mesoscopic superconductors: size effects

Flux-flow phenomena in a superconducting mesoscopic stripe submitted to an applied current and external magnetic field is studied. The time-dependent Ginzburg-Landau equations are solved numerically to obtain the electric and magnetic response of the system. It is shown that the I-V curves, for the wider strips, present a universal behaviour. The dependence of the flux-flow resistivity on the magnetic field and width allow us to propose a criterion characterizing, both, the macroscopic and mesoscopic regimes. The power spectrum of the average voltage permits identifying the effect of surface currents in vortices movement. Based on the maximum value of the power spectrum first harmonic we propose a geometric condition for matching between the sample dimensions and the vortex lattice parameter.