Abstract
It is shown that the interactions in a strongly correlated quasi-two-dimensional electron gas with the Fermi level lying at a saddle point (Van Hove singularity) in can give rise to superconductivity by exchange of excitations with a characteristic low electronic energy scale . Application to cuprate superconductors shows that this mechanism along with a conventional electron-phonon interaction can explain the high ’s and the anomalous behavior of the isotope shift as a function of doping.
- Received 11 October 1991
DOI:https://doi.org/10.1103/PhysRevLett.69.1264
©1992 American Physical Society