Giant Vortices Below the Surface of NbSe Detected Using Low Energy -NMR
arXiv:cond-mat/0703174 · doi:10.1103/PhysRevLett.98.167001
Abstract
A low energy radioactive beam of polarized Li has been used to observe the vortex lattice near the surface of superconducting NbSe. The inhomogeneous magnetic field distribution associated with the vortex lattice was measured using depth-resolved -detected NMR. Below one observes the characteristic lineshape for a triangular vortex lattice which depends on the magnetic penetration depth and vortex core radius. The size of the vortex core varies strongly with magnetic field. In particular in a low field of 10.8 mT the core radius is much larger than the coherence length. The possible origin of these giant vortices is discussed.
5 pages, 3 figures. Submitted to Phys. Rev. Lett