LANGEVIN-DYNAMICS STUDY OF NUCLEAR-RELAXATION TO VORTICES IN A LAYERED SUPERCONDUCTOR

We have investigated the possibility of nuclear relaxation due to the magnetic field fluctuations induced by thermal motion of (pancake) vor tices in a layered superconductor with a Langevin dynamics method. Onl y magnetic interactions between layers were taken into account. We fou nd that for low fields the vortex lattice (VL) is rigid and hardly aff ects the relaxation time T1. At higher vortex densities, for fields ac tually used in experimental NMR studies, effects may be visible. At th e melting temperature of the VL a peak in the relaxation rate is obser ved.