Quantum solids, liquids, and gases Program:Superconductivity at very high magnetic fields in ferropnictides. The effect of pairing symmetry and impurity scattering

by Alex (NHMFL, Florida State University), Gurevich (NHMFL, Florida State University)

Monday 26 Jul 2010, 13:45 → 14:45 Europe/Stockholm

An overview of recent results on the unusual behavior of ferropnictide superconductors under strong magnetic fields is given. The talk focuses on the extremely high Hc2 values, well above the BCS paramagnetic limit, anisotropy of vortex properties and manifestations of the anomalous temperature dependencies of Hc2(T) along different crystallographic directions, multiband superconductivity, and the effect of impurity scattering in different pairing scenarios. The role of anisotropic vortex fluctuations and their effect on the resistive transition and the irreversibility field in pnictides will be addressed. We also discuss our recent results on the Kondo effect induced by -particle irradiation of Nd(FeAs))OF single crystals and the resulting anomalously weak suppression of Tc by magnetic defects inconsistent with current theoretical models.