Using high resolution angle-resolved photoemission data in conjunction with that from neutron and other probes, we show that electron-phonon (el-ph) coupling is strong in cuprates superconductors and it plays an important role in pairing. In addition to the strong electron correlation, the inclusion of phonons provides a theoretical framework explaining many important phenomena that cannot be understood by a strongly correlated electronic model alone. Especially it is indispensable to explain the difference among materials. The phonons with the wave number around the (0,qx) and (qx,0) axes create the d-wave pairing while that near (pi,pi) are pair breaking. Therefore the half-breathing mode of the oxygen motions helps d-wave superconductivity.
@article{arxiv.cond-mat/0102244,
title = {Key Ingredients for Superconductivity in Cuprates},
author = {Z. -X. Shen and A. Lanzara and N. Nagaosa},
journal= {arXiv preprint arXiv:cond-mat/0102244},
year = {2007}
}