Disordered vortex matter out of equilibrium: a Langevin molecular dynamics study

Abstract

© 2016 Informa UK Limited, trading as Taylor & Francis Group. We discuss the use of Langevin molecular dynamics in the investigation of the non-equilibrium properties of disordered vortex matter. Our special focus is set on values of system parameters that are realistic for disordered high- (Formula presented.) superconductors such as YBCO. Using a discretised elastic line model, we study different aspects of vortices far from thermal equilibrium. On the one hand, we investigate steady-state properties of driven magnetic flux lines in a disordered environment, namely the current–voltage characteristics, the gyration radius and the pinning time statistics. On the other hand, we study the complex relaxation processes and glassy-like dynamics that emerge in type-II superconductors due to the intricate competition between the long-range vortex–vortex repulsion and flux pinning due to randomly placed point defects. To this end, we consider different types of sudden perturbations: temperature, magnetic field and external current quenches.