Abstract
We find that the planar and apical NMR spin-lattice relaxation rate and the spin-echo decay rate are spatially dependent in the mixed state of For both sites, and increase by a factor of 2 to 3 for nuclei close to the vortex cores. The data suggest that fluctuating fields from the low-frequency vibrations of the vortex lattice give rise to the similar echo decay observed at both sites. These vibrations also dominate for both sites below Above this temperature, the planar is dominated by spin-flip scattering with delocalized quasiparticles associated with the nodes in the superconducting gap showing that the position dependence arises from the effect of the supercurrents on the quasiparticle energy spectrum.
- Received 1 February 2000
DOI:https://doi.org/10.1103/PhysRevB.62.3473
©2000 American Physical Society