VORTEX FLUCTUATION EFFECTS TO MU-SR LINEWIDTH IN HIGH-TEMPERATURE SUPERCONDUCTOR

Muon spin rotation experiments have been reported to measure the magne tic penetration depth of superconductors. In many such experiments, an unexpected magnetic-field dependence is observed, which is in contrad iction with the London theory for a static flux lattice. An explanatio n of this field dependence including vortex fluctuation effects is giv en in this article.