We investigate the effect of magnetic impurities on the local quasiparticle
density of states (LDOS) in iron-based superconductors. Employing the
two-orbital model where 3d electron and hole conduction bands are hybridizing
with the localized f-orbital of the impurity spin, we investigate how various
symmetries of the superconducting gap and its nodal structure influence the
quasiparticle excitations and impurity bound states. We show that the bound
states behave qualitatively different for each symmetry. Most importantly we
find that the impurity-induced bound states can be used to identify the nodal
structure of the extended s-wave symmetry (S±) that is actively
discussed in ferropnictides.Comment: 7 pages, 5 figures, theory part is extended, figures are replace