The impurity effect in iron pnictide superconductors

The impurity in superconducting material affects the paring symmetry remarkably. The
isotropic s-wave superconductivity is insensitive to non-magnetic impurities according to Anderson’s theorem, while the s+- superconductivity is sensitive to non-magnetic impurities when inter-band electrons are scattered by the impurities, and insensitive when scattering happens between intra-band electrons. Zinc-doping is considered to induce the inter-band electrons scattering with a suppressing on s+- superconductivity.
In this research project, we will study how the impurities affect on the superconductivity.
For details, Please refer to the attachment.