Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Correlated Electrons - Poster Session

TT 20.76: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Dominant particle-hole contributions to the phonon dynamics in the spinless one-dimensional Holstein model — •Steffen Sykora, Arnd Hübsch, and Klaus Becker — Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany

In the spinless Holstein model at half-filling the coupling of electrons to phonons is responsible for a phase transition from a metallic state at small coupling to a Peierls distorted insulated state when the electron-phonon coupling exceeds a critical value. For the adiabatic case of small phonon frequencies, the transition is accompanied by a phonon softening at the Brillouin zone boundary whereas a hardening of the phonon mode occurs in the anti-adiabatic case. The phonon dynamics studied in this poster do not only reveal the expected renormalization of the phonon modes but also show remarkable additional contributions due to electronic particle-hole excitations.