Nonequilibrium steady states of driven magnetic flux lines in disordered type-II superconductors

• Published in: Superconductor science & technology Vol. 23; no. 2
• Main Authors: Klongcheongsan, T., Bullard, T. J., Täuber, U. C.
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 23.12.2009
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
• ISSN: 0953-2048; 1361-6668

We investigate driven magnetic flux lines in layered type-II superconductors subject to various configurations of strong point or columnar pinning centers by means of a three-dimensional elastic line model and Metropolis Monte Carlo simulations. We characterize the resulting nonequilibrium steady states by means of the force–velocity/current–voltage curve, static structure factor, mean vortex radius of gyration, number of double-kink and half-loop excitations, and velocity/voltage noise spectrum. Here, we compare the results for the above observables for randomly distributed point and columnar defects, and demonstrate that the three-dimensional flux line structures and their fluctuations lead to a remarkable variety of complex phenomena in the steady-state transport properties of bulk superconductors.