Superconducting properties of negative-U centers materials : Chalcogenides, cuprate oxides and fullerides

If the concentration of negative-U centers is enough to create the pair band states, this can lead to superconductivity (negative-U centers model of superconductivity) because Anderson pairs are Bose particles. In the present paper it has been shown that several puzzling superconductivity properties of chalcogenides, high-temperature cuprate superconductors and fullerides are similar for these three groups of materials and can be naturally explained in the frame of negative-U centers model of superconductivity - NUCS model.