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arXiv · 0903.5547

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

A. V. Chubukov·M. G. Vavilov·A. B. Vorontsov
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Abstract

We discuss the structure of the superconducting gap in iron pnictides. In the itinerant electron picture, gaps with or without nodes have the extended s-wave (s+) symmetry and emerge within the same pairing mechanism, determined by the interplay between intra-pocket repulsion and inter-band pair hopping. If the pair hopping is stronger, the system develops an s+ gap without nodes. In the opposite case the superconductivity is governed by of the momentum-dependent part of the pair-hopping, and an s+ gap shows nodes on electron Fermi surfaces. We argue that the gap without/with nodes emerges in systems with a stronger/weaker tendency towards a spin-density-wave order.

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A. V. Chubukov, M. G. Vavilov, A. B. Vorontsov. 2009-03-31. Momentum dependence and nodes of the superconducting gap in iron-pnictides. https://doi.org/10.1103/physrevb.80.140515

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