Relevance of phonon dynamics in strongly correlated systems coupled to phonons: A Dynamical Mean Field Theory analysis

摘要

The properties of the electron-phonon interaction in the presence of asizable electronic repulsion at finite doping are studied by investigating themetallic phase of the Hubbard-Holstein model with Dynamical Mean Field Theory.Analyzing the quasiparticle weight at finite doping, we find that a largeCoulomb repulsion reduces the effect of electron-phonon coupling at low-energy,while this reduction is not present at high energy. The renormalization of theelectron-phonon coupling induced by the Hubbard repul sion depends in asurprisingly strong and non-trivial way on the phonon frequency. Our resultssuggest that phonon might affect differently high-energy and low-energyproperties and this, together with the effect of phonon dynamics, should becarefully taken into account when the effects of the electron-phononinteraction in a strongly correlated system, like the superconducting cuprates,are discussed.