title: Plasmons in strongly correlated systems: spectral weight transfer and renormalized dispersion.
abstract: We study the charge-density dynamics within the two-dimensional extended Hubbard model in the presence of long-range Coulomb interaction across the metal-insulator transition point. To take into account strong correlations we start from self-consistent extended dynamical mean-field theory and include nonlocal dynamical vertex corrections through a ladder approximation to the polarization operator. This is necessary to fulfill charge conservation and to describe plasmons in the correlated state. The calculated plasmon spectra are qualitatively different from those in the random-phase approximation: they exhibit a spectral density transfer and a renormalized dispersion with enhanced deviation from the canonical √q behavior. Both features are reminiscent of interaction induced changes found in single-electron spectra of strongly correlated systems.
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, NL-6525 AJ Nijmegen, Netherlands.
authors.forename: E G C P
authors.initials: EG
authors.lastname: van Loon
authors.affiliation: Institut de Physique Théorique (IPhT), CEA, CNRS, 91191 Gif-sur-Yvette, France.
authors.forename: H
authors.initials: H
authors.lastname: Hafermann
authors.affiliation: I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, D-20355 Hamburg, Germany and Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia.
authors.forename: A I
authors.initials: AI
authors.lastname: Lichtenstein
authors.affiliation: Department of Physics, Moscow State University, 119991 Moscow, Russia and Russian Quantum Center, Novaya street, 100, Skolkovo, Moscow region 143025, Russia.
authors.forename: A N
authors.initials: AN
authors.lastname: Rubtsov
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, NL-6525 AJ Nijmegen, Netherlands and Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia.
authors.forename: M I
authors.initials: MI
authors.lastname: Katsnelson