Electron-phonon coupling effects explored by inelastic neutron scattering

This article gives a summary of inelastic neutron scattering studies searching for signatures of a strong electron-phonon coupling in high temperature superconductors. Special emphasis is laid on the anomalous dispersion, the unusually large linewidths and the anomalous temperature dependence observed for plane polarized copper-oxygen bond-stretching vibrations. It will be discussed in how far these results can be understood within conventional density functional theory or require recourse to theories for strongly correlated electrons, in particular the concept of charge stripe order. (C) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.