The interplay between structural or antiferromagnetic phase transition and superconductivity

Abstract The properties of high T s superconductors are investigated in a model in which superconductivity is enhanced by the singularity in the density of states generated as a result of structural or antiferromagnetic phase transition. The absence of the isotope effect and the possibility of large scale variation of the ratio 2Δ s (0)/ T s are shown to take place in this model. A strong interaction version of the model is presented.