Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 72: Poster Session: Correlated Electrons
TT 72.80: Poster
Mittwoch, 14. März 2018, 15:00–19:00, Poster B
Lattice dynamics of palladium in the presence of many-body effects — •Wilhelm Appelt1,3, Andreas Östlin2, Ivan Leonov2, Michael Sekania2, and Liviu Chioncel2,3 — 1Theoretical Physics II, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany — 2Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany — 3Augsburg Center for Innovative Technologies, University of Augsburg, 86135 Augsburg, Germany
We present theoretical results on the phonon spectrum of palladium. A combination of the local density approximation (LDA) and dynamical mean-field theory (DMFT) is employed in order to investigate the interplay between correlated electrons and lattice degrees of freedom. A good agreement with experimental dispersion curves is found for the realistic local Coulomb interaction (U=1 eV) and the local Hund’s rule coupling (J=0.3 eV). The Kohn anomaly along the Σ-line is observed on the level of LDA when computed at the experimental volume. When supplement with local electronic interactions, of Hubbard-type, we find that the kink along the Σ-line in the phonon dispersion curve is smoothened. Corrections in lowest order perturbation theory are used in order to study the influence of non-adiabatic self-energy effects on the phonon propagtor. This simple correction to the Born-Oppenheimer approximation allows us to access phonon lifetimes in the LDA+DMFT study.