Model for superconductivity in optimally doped electron cuprates

The very anomalous normal state properties and superconductivity of electron-doped superconducting cuprates with the T-* structure are discussed. The high values of the electron and hole mobilities in the literature are explained by the electrons and holes existing in different layers. The annealing procedures necessary for superconductivity produce oxygen-vacancy negative-U pairing centers. The relative insensitivity of T-c to the annealing condition is attributed to stabilization of the chemical potential near the middle of the narrow oxygen band formed by oxygen vacancies, where the electronic entropy is large. (C) 2001 American Institute of Physics.