title: Local electron-electron interaction strength in ferromagnetic nickel determined by spin-polarized positron annihilation.
abstract: We employ a positron annihilation technique, the spin-polarized two-dimensional angular correlation of annihilation radiation (2D-ACAR), to measure the spin-difference spectra of ferromagnetic nickel. The experimental data are compared with the theoretical results obtained within a combination of the local spin density approximation (LSDA) and the many-body dynamical mean-field theory (DMFT). We find that the self-energy defining the electronic correlations in Ni leads to anisotropic contributions to the momentum distribution. By direct comparison of the theoretical and experimental results we determine the strength of the local electronic interaction U in ferromagnetic Ni as 2.0 ± 0.1 eV.
authors.affiliation: Technische Universität München, Lehrstuhl E21, James-Franck Straße, 85748 Garching, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Ceeh
authors.forename: Josef Andreas
authors.initials: JA
authors.lastname: Weber
authors.affiliation: Technische Universität München, Lehrstuhl E21, James-Franck Straße, 85748 Garching, Germany.
authors.forename: Josef Andreass
authors.initials: JA
authors.lastname: Weber
authors.affiliation: Technische Universität München, Lehrstuhl E21, James-Franck Straße, 85748 Garching, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Böni
authors.affiliation: Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, 85748 Garching, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Leitner
authors.affiliation: Chemistry Department, University Munich, Butenandstraße 5-13, 81377 München, Germany.|Faculty of Physics, Babes-Bolyai University, Kogălniceanustr 1, 400084 Cluj-Napoca, Romania.
authors.forename: Diana
authors.initials: D
authors.lastname: Benea
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.|Augsburg Center for Innovative Technologies, University of Augsburg, 86135 Augsburg, Germany.
authors.forename: Liviu
authors.initials: L
authors.lastname: Chioncel
authors.affiliation: Chemistry Department, University Munich, Butenandstraße 5-13, 81377 München, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Ebert
authors.affiliation: Chemistry Department, University Munich, Butenandstraße 5-13, 81377 München, Germany.|New Technologies - Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Minár
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Vollhardt
authors.affiliation: Technische Universität München, Lehrstuhl E21, James-Franck Straße, 85748 Garching, Germany.|Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, 85748 Garching, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hugenschmidt