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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.38: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Analytical approach to the quantum-phase transition in the one-dimensional spinless Holstein model — •Steffen Sykora¹, Arnd Hübsch², and Klaus W. Becker¹ — ¹Institut für Theoretische Physik, Technische Universität Dresden, D-01062 Dresden, Germany — ²Department of Physics, University of California, CA 95616, USA

We study the one-dimensional Holstein model of spinless fermions interacting with dispersion-less phonons by using a recently developed projector-based renormalization method (PRM). At half-filling the system shows a metal-insulator transition to a Peierls distorted state at a critical electron-phonon coupling where both phases are described within the same theoretical framework. The transition is accompanied by a phonon softening at the Brillouin zone boundary and a gap in the electronic spectrum. For different filling, the phonon softening appears away from the Brillouin zone boundary and thus reflects a different type of broken symmetry state.