FLUX MOTION AND RESISTANCE IN HIGH-TEMPERATURE SUPERCONDUCTORS - AN OVERVIEW

Study of flux motion and resistance in the new superconductors is of interest both for achievement of usefully low resistance at usefully large current densities, and for conceptual understanding of the idealized resistive behavior in the zero current limit. Some analyses emphasize the collective aspects of the interacting flux lines, whether liquid, solid, crystalline, or glassy; others emphasize the pinning of individual flux lines to material inhomogeneities; still others emphasize percolative Josephson coupling between grains. An overview is given of these approaches, their interrelation, and the experimental evidence, plus some new results on flux motion in large SNS arrays, treated as a model system.