DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2011 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 2: SC: Properties, Electronic Structure, Mechanisms 1

TT 2.4: Talk

Monday, March 14, 2011, 11:15–11:30, HSZ 301

Low-energy kink in the nodal dispersion of copper-oxide superconductors: Insights from Dynamical Mean Field Theory — •Johannes Bauer1 and Giorgio Sangiovanni21Max-Planck Institute for Solid State Research, Heisenbergstr.1, 70569 Stuttgart — 2Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria

Motivated by the observation in copper-oxide high-temperature superconductors, we investigate the appearance of kinks in the electronic dispersion due to coupling to phonons for a system with strong electronic repulsion. We study a Hubbard model supplemented by an electron-phonon coupling of Holstein type within Dynamical Mean Field Theory (DMFT) utilizing Numerical Renormalization Group as impurity solver. Paramagnetic DMFT solutions in the presence of large repulsion show a kink only for large values of the electron-phonon coupling λ or large doping and, contrary to the conventional electron-phonon theory, the position of such a kink can be shifted to energies larger than the renormalized phonon frequency ω0r. When including antiferromagnetic correlations we find a stronger effect of the electron-phonon interaction on the electronic dispersion due to a cooperative effect and a visible kink at ω0r, even for smaller λ [1]. Our results provide a scenario of a kink position increasing with doping, which can be related to recent photoemission experiments on Bi-based cuprates.
J. Bauer and G. Sangiovanni, Phys. Rev. B. 82, 184535 (2010).

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2011 > Dresden