Momentum dependence and nodes of the superconducting gap in the iron pnictides
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.
- Publication:
-
Physical Review B
- Pub Date:
- October 2009
- DOI:
- 10.1103/PhysRevB.80.140515
- arXiv:
- arXiv:0903.5547
- Bibcode:
- 2009PhRvB..80n0515C
- Keywords:
-
- 74.20.Rp;
- 74.25.Nf;
- 74.62.Dh;
- Pairing symmetries;
- Response to electromagnetic fields;
- Effects of crystal defects doping and substitution;
- Condensed Matter - Superconductivity
- E-Print:
- 5pp, 3 figures