SPATIAL INHOMOGENEITIES IN VORTEX PINNING: A PROBE FOR NANOSCALE DISORDER IN CUPRATES AND PNICTIDE SUPERCONDUCTORS

FASANO Y.; N.R. CEJAS BOLECEK; A. B. KOLTON; H. PASTORIZA; D. DOMÍNGUEZ; C.J. VAN DER BEEK

S. C. de Bariloche

Conferencia; Advanced Topics in Magnetism and Superconductivity AToMS-2014; 2014

Centro Atómico Bariloche

Quantifying the effects of material disorder is important for the understanding of the differences in the superconducting ground state of cuprates and new pnictides high-temperature superconductors. For both families of superconductors, the proximity of the superconducting state to anti-ferromagnetism may lead to phase segregation that will be heavily influenced by heterogeneity due to the chemical and crystalline disorder of the materials. In the case of the pnictides, the superconducting ground state in was proposed to have a s ± symme- try, in which case superconductivity might be extremely sensitive to interband scattering. The effect of impurities for interband scattering is usually characterized by the quasiparticles scattering rate. A well-known but little exploited probe of microscopic disorder is the pinning of vortex lines in the superconducting mixed state. In this work we study the spatial inho- mogeneities in the single-vortices pinning force in order to quantify the effect of nanoscale disorder introduced or naturally found in iron-based pnictides and high-temperature cuprates by combining vortex imaging with single-vortex resolution by means of magnetic decoration and microscopic disorder properties from critical current measurements