Dobramysl Ulrich, Pleimling Michel, Täuber Uwe C
Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom.
Department of Physics (MC 0435), Virginia Tech, Blacksburg, Virginia 24061, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Dec;90(6):062108. doi: 10.1103/PhysRevE.90.062108. Epub 2014 Dec 2.
We study the pinning dynamics of magnetic flux (vortex) lines in a disordered type-II superconductor. Using numerical simulations of a directed elastic line model, we extract the pinning time distributions of vortex line segments. We compare different model implementations for the disorder in the surrounding medium: discrete, localized pinning potential wells that are either attractive and repulsive or purely attractive, and whose strengths are drawn from a Gaussian distribution; as well as continuous Gaussian random potential landscapes. We find that both schemes yield power-law distributions in the pinned phase as predicted by extreme-event statistics, yet they differ significantly in their effective scaling exponents and their short-time behavior.