Momentum dependence and nodes of the superconducting gap in the iron pnictides

2009/03/31 by Andrey V. Chubukov, A. V. Chubukov, Maxim Vavilov +2 · 7 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.80.140515

published as Phys. Rev. B 80, 140515(R) (2009) · 5pp, 3 figures

arxiv created 2009/03/31 · openalex publication_date 2009/10/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Using general symmetry arguments and model calculations we analyze the superconducting gap in materials with multiple Fermi-surface pockets, with applications to iron pnictides. We show that the gap in the pnictides has an extended s-wave symmetry but is either nodeless or has nodes, depending on the interplay between intraband and interband interactions. We argue that the nodes in the gap emerge without a phase transition as the tendency toward a spin-density-wave order gets weaker. These findings provide a way to reconcile seemingly conflicting results of numerical and experimental studies of the pnictides.

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