2012/11/08 by N. Lanatà, H. U. R. Strand, G. Giovannetti +3
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.87.045122
published as Phys. Rev. B 87, 045122 (2013) · 5 pages, 4 figures
arxiv created 2012/11/08 · arxiv updated 2013/05/24
We show that electron correlations lead to a bad metallic state in chalcogenides FeSe and FeTe despite the intermediate value of the Hubbard repulsion U and Hund's rule coupling J. The evolution of the quasi particle weight Z as a function of the interaction terms reveals a clear crossover at U ≃ 2.5 eV. In the weak coupling limit Z decreases for all correlated d orbitals as a function of U and beyond the crossover coupling they become weakly dependent on U while strongly depend on J. A marked orbital dependence of the Z's emerges even if in general the orbital-selective Mott transition only occurs for relatively large values of U. This two-stage reduction of the quasi particle coherence due to the combined effect of Hubbard U and the Hund's J, suggests that the iron-based superconductors can be referred to as Hund's correlated metals.