Quasiparticle scattering interference in superconducting Oxypnictides

Based on a two-band model of the superconducting iron oxypnictides, we study the effects of single-impurity scattering on the local density of states by exact T-matrix calculations. We compare the quasi-particle interference patterns in different pairing states, as well as different kinds of impurities. The results of this calculation can be used to test and distinguish different sorts of pairing symmetries and impurities in the experiments.