title: What controls the phase diagram and superconductivity in Ru-substituted BaFe2As2?
abstract: We use high resolution angle-resolved photoemission to study the electronic structure of the iron based high-temperature superconductors Ba(Fe(1-x)Ru(x))(2)As(2) as a function of Ru concentration. We find that substitution of Ru for Fe is isoelectronic, i.e., it does not change the value of the chemical potential. More interestingly, there are no measured, significant changes in the shape of the Fermi surface or in the Fermi velocity over a wide range of substitution levels (0<x<0.55). Given that the suppression of the antiferromagnetic and structural phase is associated with the emergence of the superconducting state, Ru substitution must achieve this via a mechanism that does not involve changes of the Fermi surface. We speculate that this mechanism relies on magnetic dilution which leads to the reduction of the effective Stoner enhancement.
authors.affiliation: Division of Materials Science and Engineering, The Ames Laboratory, U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA. rsdhaka@ameslab.gov
authors.forename: R S
authors.initials: RS
authors.lastname: Dhaka
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.forename: R M
authors.initials: RM
authors.lastname: Fernandes
authors.forename: Rui
authors.initials: R
authors.lastname: Jiang
authors.forename: C P
authors.initials: CP
authors.lastname: Strehlow
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: A
authors.initials: A
authors.lastname: Thaler
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmalian
authors.forename: S L
authors.initials: SL
authors.lastname: Bud'ko
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield
authors.forename: Adam
authors.initials: A
authors.lastname: Kaminski