[工程科技]Importance of the Electron-Phonon Interaction with the Forward Scattering Peak for Supercon.pdf

Importance of the Electron-Phonon Interaction with the Forward Scattering Peak for Superconducting Pairing in Cuprates Miodrag L. Kuli´c J. W. Goethe-Universit¨at Frankfurt am Main, Theoretische Physik, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main, Germany 6 (Dated: February 6, 2008) 0 0 We discuss first some basic experimental facts related to ARPES, tunnelling, optics ad neutron 2 scattering measurements. They give evidence for the relevance of the electron-phonon interaction (EPI) in pairing mechanism of HTSC cuprates. A controllable and very efficient theory for strong n correlations and their effects on EPI is discussed. The theory is based on the 1/N expansion u method in the t-J model without using slave bosons (or fermions). The remarkable prediction J is that strong correlations renormalize EPI and other charge-fluctuation properties (by including 2 nonmagnetic impurity scattering) in such a way that the forward scattering peak (FSP) appears in the corresponding effective interactions. The existence of FSP in EPI is additionally supported ] n by the weakly screened Madelung interaction in the ionic-metallic structure of layered cuprates. o Pronounced FSP in EPI of HTSC cuprates reconciles many puzzling results, which could not be c explained by the old theory with the momentum indepe