Document Type

Article

Publication Version

Published Version

Publication Date

4-18-2014

Journal or Book Title

Physical Review Letters

Volume

112

Issue

15

First Page

15641

DOI

10.1103/PhysRevLett.112.156401

Abstract

For solid-solution Ba1−xKxFe2As2 Fermi surface evolution is mapped via Bloch spectral functions calculated using density functional theory implemented in Korringa-Kohn-Rostoker multiple scattering theory with the coherent-potential approximation. Spectral functions reveal electronic dispersion, topology, orbital character, and broadening (electron-lifetime effects) due to chemical disorder. Dissolution of electron cylinders occurs near x∼0.9 with a nonuniform, topological (Lifshitz) transition, reducing the interband interactions; yet the dispersion maintains its dxz or dyz character. Formation energies indicate alloying at x=0.35, as observed, and a tendency for segregation on the K-rich (x>0.6) side, explaining the difficulty of controlling sample quality and the conflicting results between characterized electronic structures. Our results reveal Fermi surface transitions in alloyed samples that influence s± to nodal superconductivity and suggest the origin for deviations of common trends in Fe-based superconductors, such as Bud’ko-Ni-Canfield scaling.

Comments

This article is from Phys. Rev. Lett. 112, 156401 (2014), doi:10.1103/PhysRevLett.112.156401. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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