Origin of Gap Anisotropy in Spin Fluctuation Models of the Fe-pnictides

Abstract

We discuss the large gap anisotropy found for the A1g (s-wave) state in RPA spin-fluctuation and functional renormalization group calculations and show how the simple arguments leading to isotropic sign-switched s-wave states in these systems need to be supplemented by a consideration of pair scattering within Fermi surface sheets and between the individual electron sheets as well. In addition, accounting for the orbital makeup of the states on the Fermi surface is found to be crucial.

6 pages, 7 figures

References in corpus (9)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Proximity of antiferromagnetism and superconductivity in LaO${}_{1-x}$F${}_x$FeAs: effective Hamiltonian from ab initio studies
• NMR relaxation rate in superconducting pnictides: extended $s_{\pm }$ scenario
• Spin Fluctuations, Interband Coupling, and Unconventional Pairing in Iron-based Superconductors
• Lifting of nodes by disorder in extended-$s$ state superconductors: application to ferropnictides
• Superfluid density and penetration depth in Fe-pnictides
• On superconducting and magnetic properties of iron-oxypnictides

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• Tight binding model for iron pnictides
• Superconducting fluctuations in the reversible magnetization of the iron-pnictide $B{a}_{1-x}{K}_{x}F{e}_{2}A{s}_2$