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.
Original language | English (US) |
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Article number | 140515 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 80 |
Issue number | 14 |
DOIs | |
State | Published - Oct 29 2009 |