Expansion of vortex cores by strong electronic correlation in La_{2x}Sr_{x}CuO_{4} at low magnetic induction
Abstract
The vortex core radius ρ_{v}, defined as the peak position of the supercurrent around the vortex, has been determined by muon spin rotation measurements in the mixed state of La_{2x}Sr_{x}CuO_{4} for x=0.13, 0.15, and 0.19. At lower doping (x=0.13 and 0.15), ρ_{v}(T) increases with decreasing temperature T, which is opposite to the behavior predicted by the conventional theory. Moreover, ρ_{v}(T→0) is significantly larger than the GinzburgLandau coherence length determined by the upper critical field, and shows a clear tendency to decrease with increasing the doping x. These features can be qualitatively reproduced in a microscopic model involving antiferromagnetic electronic correlations.
 Publication:

Physical Review B
 Pub Date:
 March 2004
 DOI:
 10.1103/PhysRevB.69.104523
 arXiv:
 arXiv:condmat/0402064
 Bibcode:
 2004PhRvB..69j4523K
 Keywords:

 74.25.Op;
 74.25.Qt;
 76.75.+i;
 Mixed states critical fields and surface sheaths;
 Vortex lattices flux pinning flux creep;
 Muon spin rotation and relaxation;
 Condensed Matter  Superconductivity;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 6 pages, 4 figures, to be published in Phys. Rev. B