Magnetic impurity scattering effects induce C2 symmetry in iron-based superconductors

Highlights: • We study the magnetic impurity effects in iron-based superconductors. • We study the quasiparticle interference effect in two impurities system. • The magnetic scattering play a primary role in the appearance of the C2 symmetry. - Abstract: We consider the effect of magnetic impurities, modeled by classical spins, in iron-based superconductors. By using a self-consistent Bogoliubov–de Gennes formalism, we show that one magnetic impurity scattering exhibits pronounced two fold symmetry (C2) in iron-based superconductors. We also study the effects of quantum interference in impurity structures consisting of two magnetic impurities. We show that the quantum interference leads to characteristic signatures of twofold symmetry not only in the local density of states (LDOS), but also in the spatial form of the superconducting order parameter. We suggest that these results deserve more attention in the analysis of C2 symmetry found in scanning tunneling microscopy experiments for different iron-based superconductors