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Spectral properties and bandstructure of correlated electron systems

Thomas Pruschke, Th. Obermeier, J. Keller +1 more

arXiv:cond-mat/9510022Physica B Condensed MatterJun 1, 199612 citations

Effective mass of quasiparticles in at-Jmodel with electron-phonon interactions

A. Ramšak, Peter Horsch, Peter Fulde

The change of the spectral properties of the single-particle Green's function due to a coupling to optical phonons is investigated for strongly correlated electrons. The phonon-induced mass renormalization of the carriers that propagate in the t-J model on scale J is much larger than in the corresponding uncorrelated model, except in the limit of J\ensuremath{\rightarrow}0 where the weight of the quasiparticle pole tends to zero. The enhancement is a consequence of the slow coherent motion of the spin polarons, which makes electron-phonon interactions more effective. Two scaling laws are determined which relate the mass renormalization to phonon frequency and coupling constant.The change of the spectral properties of the single-particle Green's function due to a coupling to optical phonons is investigated for strongly correlated electrons. The phonon-induced mass renormalization of the carriers that propagate in the t-J model on scale J is much larger than in the corresponding uncorrelated model, except in the limit of J\ensuremath{\rightarrow}0 where the weight of the quasiparticle pole tends to zero. The enhancement is a consequence of the slow coherent motion of the spin polarons, which makes electron-phonon interactions more effective. Two scaling laws are determined which relate the mass renormalization to phonon frequency and coupling constant.

Physical review. B, Condensed matterDec 1, 199254 citations

Electron-phonon interaction in strongly correlated systems

V. A. Moskalenko

Theoretical and Mathematical PhysicsJun 1, 199711 citations

Effects of electron-phonon coupling range on the polaron formation

C. A. Perroni, V. Cataudella, G. De Filippis +1 more

The polaron features due to electron-phonon interactions with different coupling ranges are investigated by adopting a variational approach. The ground-state energy, the spectral weight, the average kinetic energy, the mean number of phonons, and the electron-lattice correlation function are discussed for the system with coupling to local and nearest-neighbor lattice displacements comparing the results with the long-range case. For large values of the coupling with nearest-neighbor sites, most physical quantities show a strong resemblance with those obtained for the long-range electron-phonon interaction. Moreover, for intermediate values of interaction strength, the correlation function between electron and nearest-neighbor lattice displacements is characterized by an upturn as function of the electron-phonon coupling constant.The polaron features due to electron-phonon interactions with different coupling ranges are investigated by adopting a variational approach. The ground-state energy, the spectral weight, the average kinetic energy, the mean number of phonons, and the electron-lattice correlation function are discussed for the system with coupling to local and nearest-neighbor lattice displacements comparing the results with the long-range case. For large values of the coupling with nearest-neighbor sites, most physical quantities show a strong resemblance with those obtained for the long-range electron-phonon interaction. Moreover, for intermediate values of interaction strength, the correlation function between electron and nearest-neighbor lattice displacements is characterized by an upturn as function of the electron-phonon coupling constant.

arXiv:cond-mat/0411651Physical Review BFeb 4, 200513 citations

Spectral properties of strongly correlated systems

H. Monien

Physica B Condensed MatterJan 1, 19980 citations

Relevance of phonon dynamics in strongly correlated systems coupled to phonons: Dynamical mean-field theory analysis

Giorgio Sangiovanni, Massimo Capone, Claudio Castellani

The properties of the electron-phonon interaction in the presence of a sizable electronic repulsion at finite doping are studied by investigating the metallic phase of the Hubbard-Holstein model with dynamical mean-field theory. Analyzing the quasiparticle weight at finite doping, we find that a large Coulomb repulsion reduces the effect of electron-phonon coupling at low energy, while this reduction is not present at high energy. The renormalization of the electron-phonon coupling induced by the Hubbard repulsion depends in a surprisingly strong and nontrivial way on the phonon frequency. Our results suggest that phonon might affect differently high-energy and low-energy properties and this, together with the effect of phonon dynamics, should be carefully taken into account when the effects of the electron-phonon interaction in a strongly correlated system, like the superconducting cuprates, are discussed.The properties of the electron-phonon interaction in the presence of a sizable electronic repulsion at finite doping are studied by investigating the metallic phase of the Hubbard-Holstein model with dynamical mean-field theory. Analyzing the quasiparticle weight at finite doping, we find that a large Coulomb repulsion reduces the effect of electron-phonon coupling at low energy, while this reduction is not present at high energy. The renormalization of the electron-phonon coupling induced by the Hubbard repulsion depends in a surprisingly strong and nontrivial way on the phonon frequency. Our results suggest that phonon might affect differently high-energy and low-energy properties and this, together with the effect of phonon dynamics, should be carefully taken into account when the effects of the electron-phonon interaction in a strongly correlated system, like the superconducting cuprates, are discussed.

arXiv:cond-mat/0512020Physical Review BApr 21, 200643 citations

Spectral properties of correlated systems with electron-phonon coupling

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