2010/02/01 by Andreas Glatz, A. Glatz, A. E. Koshelev
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.82.012507
published as Phys. Rev. B 82, 012507 (2010) · 7 pages, 5 figures, RevTex 4.1
arxiv created 2010/02/01 · openalex publication_date 2010/07/21 · arxiv updated 2011/08/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
There is strong support in favor of an unusual s_\ifmmode±\else\textpm\fi superconducting state in the recently discovered iron-based superconductors in which the gap parameter has opposite signs in different bands. In this case, scattering between different bands by impurities has a pair-breaking effect and introduces states inside the gap. We studied the statistics of disorder-induced subgap states in s_\ifmmode±\else\textpm\fi superconductors due to collective effects of impurities. Numerically solving the two-band Bogolyubov equations, we explored the behavior of the density of states and localization length. We located the mobility edge separating the localized and delocalized states for the three-dimensional case and the crossover between the weak and strong localization regimes for the two-dimensional case. We found that the widely used self-consistent T-matrix approximation is not very accurate in describing subgap states.