Interaction-induced singular Fermi surface in a high-temperature oxypnictide superconductor

Charnukha, A and Thirupathaiah, S and Zabolotnyy, VB and Buechner, B and Zhigadlo, ND and Batlogg, B and Yaresko, AN and Borisenko, SV (2015) Interaction-induced singular Fermi surface in a high-temperature oxypnictide superconductor. In: SCIENTIFIC REPORTS, 5 .

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Abstract

In the family of iron-based superconductors, LaFeAsO-type materials possess the simplest electronic structure due to their pronounced two-dimensionality. And yet they host superconductivity with the highest transition temperature T-c approximate to 55K. Early theoretical predictions of their electronic structure revealed multiple large circular portions of the Fermi surface with a very good geometrical overlap (nesting), believed to enhance the pairing interaction and thus superconductivity. The prevalence of such large circular features in the Fermi surface has since been associated with many other iron-based compounds and has grown to be generally accepted in the field. In this work we show that a prototypical compound of the 1111-type, SmFe0.92Co0.08AsO, is at odds with this description and possesses a distinctly different Fermi surface, which consists of two singular constructs formed by the edges of several bands, pulled to the Fermi level from the depths of the theoretically predicted band structure by strong electronic interactions. Such singularities dramatically affect the low-energy electronic properties of the material, including superconductivity. We further argue that occurrence of these singularities correlates with the maximum superconducting transition temperature attainable in each material class over the entire family of iron-based superconductors.

Item Type:	Journal Article
Publication:	SCIENTIFIC REPORTS
Publisher:	NATURE PUBLISHING GROUP
Additional Information:	Copy right for this article belongs to the NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	19 Jul 2015 09:20
Last Modified:	19 Jul 2015 09:20
URI:	http://eprints.iisc.ac.in/id/eprint/51824

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