Interband Model Scenario of Cuprate Superconductivity

A multiband approach for hole- and electron-doped cuprate superconductors is developed. The model electron spectrum includes nodal and antinodal defect (polaronic) subbands created by doping. Bare gaps between itinerant and defect subbands close with extended doping. The overlap conditions determine phase diagram special points. There are analogies for both types of doping despite the activation of different sublattices. Illustrative calculations have given self-consistent results reproducing qualitatively doping dependences of T (c) , superconducting gaps and pseudogaps, supercarrier density and effective mass, coherence length and penetration depth, etc. Interband pairing scenario is suggested to be an essential aspect of cuprate superconductivity.