Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 6: Correlated Electrons - (General) Theory I
TT 6.4: Vortrag
Freitag, 4. März 2005, 14:45–15:00, TU H2053
Electron-phonon interaction in strongly correlated materials — •Oliver Rösch and Olle Gunnarsson — Max-Planck-Institut für Festkörperforschung, Heisenbergstr.1, 70569 Stuttgart
We study the interplay of electron-phonon and eletron-electron interactions for a t-J model with electron-phonon coupling. Using exact sum rules, we find that the effect of the electron-phonon interaction on the phonon self-energy is strongly suppressed at low doping, while there is no corresponding suppression for the electron self-energy or the phonon-induced electron-electron interaction.1
Photoemission experiments suggest polaronic behavior in undoped cuprates due to coupling to bosons. Calculating the electron-phonon interaction in a shell model, we find sufficiently strong coupling to give polaronic behavior. Using an adiabatic approximation we explain why the broad peak from phonon sidebands shows a dispersion consistent with that of a quasi-particle in a purely electronic model without electron-phonon interaction.2
[1] O. Rösch and O. Gunnarsson, cond-mat/0407064,
[1] Phys. Rev. Lett. in press.
[2] O. Rösch and O. Gunnarsson, cond-mat/0410247.