Vortex avalanches with robust statistics observed in superconducting niobium

Abstract

By combining micro-Hall probe and magneto-optical imaging techniques we have been able to examine vortex avalanches at different locations of the ridgelike magnetic topography of superconducting niobium samples as the external field is slowly increased. The avalanche size distributions are shown to be power laws for two decades with very similar critical exponents at all locations, thus demonstrating a remarkable robustness in the details of the flux penetration dynamics.