title: Electronic correlations and unconventional spectral weight transfer in the high-temperature pnictide BaFe(2-x)Co(x)As(2) superconductor using infrared spectroscopy.
abstract: We report an infrared optical study of the pnictide high-temperature superconductor BaFe(1.84)Co(0.16)As(2) and its parent compound BaFe(2)As(2). We demonstrate that electronic correlations are moderately strong and do not change across the spin-density wave transition or with doping. By examining the energy scale and direction of spectral weight transfer, we argue that Hund's coupling J is the primary mechanism that gives rise to correlations.
authors.affiliation: Department of Physics, University of California, San Diego, La Jolla, California 92093, USA. aschafgans@physics.ucsd.edu
authors.forename: A A
authors.initials: AA
authors.lastname: Schafgans
authors.forename: S J
authors.initials: SJ
authors.lastname: Moon
authors.forename: B C
authors.initials: BC
authors.lastname: Pursley
authors.forename: A D
authors.initials: AD
authors.lastname: LaForge
authors.forename: M M
authors.initials: MM
authors.lastname: Qazilbash
authors.forename: A S
authors.initials: AS
authors.lastname: Sefat
authors.forename: D
authors.initials: D
authors.lastname: Mandrus
authors.forename: K
authors.initials: K
authors.lastname: Haule
authors.forename: G
authors.initials: G
authors.lastname: Kotliar
authors.forename: D N
authors.initials: DN
authors.lastname: Basov