Berlin 2015 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 112: Correlated Electrons: (General) Theory 3

TT 112.2: Talk

Friday, March 20, 2015, 09:45–10:00, H 3010

Plasmons in strongly correlated systems: spectral weight transfer and renormalized dispersion — •Erik van Loon¹, Hartmut Hafermann², Alexander Lichtenstein^3,4, Rubtsov Alexey^5,6, and Mikhail Katsnelson^1,4 — ¹Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands — ²Institut de Physique Théorique, CEA, CNRS, Gif-sur-Yvette, France — ³Institut für Theoretische Physik, Universität Hamburg, Hamburg, Germany — ⁴Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Ekaterinburg, Russia — ⁵Department of Physics, Moscow State University, Moscow, Russia — ⁶Russian Quantum Center, Skolkovo, Russia

We study plasmons within the two-dimensional extended Hubbard model in the presence of long-range Coulomb interaction. Strong correlations are taken into account using self-consistent extended dynamical mean-field theory. The polarization operator is determined in the ladder approximation, which includes non-local dynamical vertex corrections. 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 the single-electron spectra of strongly correlated systems.