Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 53: Low-Dimensional Systems: 1D - Theory

TT 53.8: Vortrag

Mittwoch, 9. März 2016, 17:00–17:15, H23

Thermodynamic and spectral properties of one-dimensional electron-phonon models in the adiabatic limit — •Manuel Weber, Fakher F. Assaad, and Martin Hohenadler — Institut für Theoretische Physik und Astrophysik, Universität Würzburg, 97074 Würzburg, Germany

In one-dimensional electronic systems at half-filling, electron-phonon coupling can lead to lattice dimerization accompanied by charge-density or bond-density wave order. According to Peierls' theorem, the ground state is ordered for any nonzero coupling when quantum lattice fluctuations are neglected. In this adiabatic limit, the lattice displacements become classical variables that can be sampled in a Monte Carlo simulation. For each phonon configuration, the resulting fermionic Hamiltonian can be diagonalized exactly. Considering the Holstein model and the Su-Schrieffer-Heeger model, we study the formation of the Peierls-insulating ground state as a function of temperature. At low temperatures, we observe a peak in the specific heat associated with the opening of a band gap, and the formation of shadow bands as well as polaron signatures in the single-particle spectrum.