title: Kondo decoherence: finding the right spin model for iron impurities in gold and silver.
abstract: We exploit the decoherence of electrons due to magnetic impurities, studied via weak localization, to resolve a long-standing question concerning the classic Kondo systems of Fe impurities in the noble metals gold and silver: which Kondo-type model yields a realistic description of the relevant multiple bands, spin, and orbital degrees of freedom? Previous studies suggest a fully screened spin S Kondo model, but the value of S remained ambiguous. We perform density functional theory calculations that suggest S=3/2. We also compare previous and new measurements of both the resistivity and decoherence rate in quasi-one-dimensional wires to numerical renormalization group predictions for S=1/2, 1, and 3/2, finding excellent agreement for S=3/2.
authors.affiliation: Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: T A
authors.initials: TA
authors.lastname: Costi
authors.forename: L
authors.initials: L
authors.lastname: Bergqvist
authors.forename: A
authors.initials: A
authors.lastname: Weichselbaum
authors.forename: J
authors.initials: J
authors.lastname: von Delft
authors.forename: T
authors.initials: T
authors.lastname: Micklitz
authors.forename: A
authors.initials: A
authors.lastname: Rosch
authors.forename: P
authors.initials: P
authors.lastname: Mavropoulos
authors.forename: P H
authors.initials: PH
authors.lastname: Dederichs
authors.forename: F
authors.initials: F
authors.lastname: Mallet
authors.forename: L
authors.initials: L
authors.lastname: Saminadayar
authors.forename: C
authors.initials: C
authors.lastname: Bäuerle