Violation of anderson's theorem for the sign-reversing s-wave state of iron-pnictide superconductors

Seiichiro Onari, Hiroshi Kontani

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226 Citations (Scopus)


Based on the five-orbital model, we study the effect of local impurity in iron pnictides, and find that the interband impurity scattering is promoted by the d-orbital degree of freedom. This fact means that the fully gapped sign-reversing s-wave state, which is predicted by spin fluctuation theories, is very fragile against impurities. In the BCS theory, only 1% impurities with intermediate strength induce huge pair breaking, resulting in the large in-gap state and prominent reduction in Tc, contrary to the prediction based on simple orbital-less models. The present study provides a stringent constraint on the pairing symmetry and the electronic states in iron pnictides.

Original languageEnglish
Article number177001
JournalPhysical Review Letters
Issue number17
Publication statusPublished - Oct 21 2009


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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