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TT: Fachverband Tiefe Temperaturen
TT 28: Correlated Electrons: Metal-Insulator Transition 1
TT 28.10: Vortrag
Donnerstag, 28. Februar 2008, 12:00–12:15, H 2053
Crossover behavior in the metallic state of the one-dimensional Holstein model — •Steffen Sykora, Arnd Hübsch, and Klaus W. Becker — Institut für Theoretische Physik, TU Dresden, Germany
The Holstein model is perhaps the simplest realization of a coupled electron-phonon system with a local interaction between dispersionless phonons of frequency ω0 and electrons with hopping matrix element t. By applying the projective renormalization method (PRM), the physical properties of the one-dimensional model in the metallic state are investigated for the adiabatic case (ω0 /t ≪ 1), for the antiadiabatic case (ω0 /t ≫ 1), as well as for the intermediate case (ω0 /t ≈ 1). As a result we find that in the adiabatic case a phonon softening is observed at the Brillouin zone boundary whereas for the opposite case a hardening is found.