Using an array of miniature Hall probes, we monitored the spatiotemporal variation of the internal magnetic induction in a superconducting niobium sample during a slow sweep of external magnetic field. We found that a sizable fraction of the increase in the local vortex population occurs in abrupt jumps. The size distribution of these avalanches presents a power-law collapse on a limited range. In contrast, at low temperatures and low fields, huge avalanches with a typical size occur and the system does not display a well-defined macroscopic critical current.
@article{arxiv.cond-mat/9902334,
title = {Internal avalanches in a pile of superconducting vortices},
author = {K. Behnia and C. Capan and D. Mailly and B. Etienne},
journal= {arXiv preprint arXiv:cond-mat/9902334},
year = {2009}
}