paper

Selective Mottness as a key to iron superconductors

arXiv:1212.3966 · doi:10.1103/PhysRevLett.112.177001

Abstract

The phase diagram of the high-Tc cuprates is dominated by the Mott insulating phase of the parent compounds. As we approach it from large doping, a standard Fermi-liquid gradually turns into a bad non-Fermi liquid metal, a process which culminates in the pseudogap regime, in which the antinodal region in momentum space acquires a gap before reaching a fully gapped Mott state. Here we show that experiments for electron- and hole-doped BaFe2As2 support an analogous scenario. The doping evolution is dominated by the influence of a Mott insulator that would be realized for half-filled conduction bands, while the stoichiometric compound does not play a special role. Weakly and strongly correlated conduction electrons coexist in much of the phase diagram, a differentiation which increases with hole doping. We identify the reason for this selective Mottness in a strong Hund's coupling, which decouples the different orbitals. Each orbital then behaves as a single band Hubbard model, where the correlation degree only depends on how doped is each orbital from half-filling. Our scenario reconciles contrasting evidences on the electronic correlation strength and establishes a deep connection with the cuprates.

Analysis of DCA data from Gull et al. PRB 82 155101 (2010) in term of the orbital-decoupling mechanism is added in the supplementary material, introduction has been rewritten, and other minor corrections

References in corpus (30)

Cited by in corpus (251)