Workshop "NMR, µSR, Mössbauer spectroscopies in the study of Fe-based and other unconventional high-Tc superconductors"
Disorder induced transition between s+- and s++ states in two-band superconductors
Dmitriy Efremov, IFW Dresden, Germany
Most of the novel superconductors are realized by chemical substitution. Two effects by chemical substitution can be identified: injection of the charge carriers and electron scattering on disorder due to dopant atoms (impurity scattering). In this talk the role of disorder in multiband superconductors (such as Fe-based superconductors) will be reviewed. It will be shown that impurities (nonmagnetic as well as magnetic) may cause changing of the symmetry of superconductive order parameter like s+- -> s++ and vice versa.