title: Existence, character, and origin of surface-related bands in the high temperature iron pnictide superconductor BaFe(2-x)Co(x)As2.
abstract: Low energy electron diffraction (LEED) experiments, LEED simulations, and finite slab density functional calculations are combined to study the cleavage surface of Co doped BaFe(2-x)Co(x)As2 (x = 0.1,0.17). We demonstrate that the energy dependence of the LEED data can only be understood from a terminating 1/2 Ba layer accompanied by distortions of the underlying As-Fe2-As block. As a result, surface-related Fe 3d states are present in the electronic structure, which we identify in angle resolved photoemission spectroscopy (ARPES) experiments. The close proximity of the surface-related states to the bulk bands inevitably leads to broadening of the ARPES signals, which excludes the use of the BaFe(2-x)Co(x)As2 system for accurate determination of self-energies using ARPES.
authors.affiliation: van der Waals-Zeeman institute, University of Amsterdam, 1018 XL Amsterdam, The Netherlands. e.vanheumen@uva.nl
authors.forename: Erik
authors.initials: E
authors.lastname: van Heumen
authors.forename: Johannes
authors.initials: J
authors.lastname: Vuorinen
authors.forename: Klaus
authors.initials: K
authors.lastname: Koepernik
authors.forename: Freek
authors.initials: F
authors.lastname: Massee
authors.forename: Yingkai
authors.initials: Y
authors.lastname: Huang
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.forename: Jesse
authors.initials: J
authors.lastname: Klei
authors.forename: Jeroen
authors.initials: J
authors.lastname: Goedkoop
authors.forename: Matti
authors.initials: M
authors.lastname: Lindroos
authors.forename: Jeroen
authors.initials: J
authors.lastname: van den Brink
authors.forename: Mark S
authors.initials: MS
authors.lastname: Golden