Cuprates: Back to the Fermi Surface

ABSTRACTThe cuprate superconductor problem is approached from the conventional metallic standpoint, valid at dopings near the Tc maximum and beyond. There is strong evidence that the Tc maximum corresponds to EF lying at a van Hove singularity, a special situation leading to Marginal Fermi Liquid behavior, and also to a minimum in the isotope shift, as observed. The superconducting properties are discussed in the light of phononic and electronic pairing models.