Superconducting gaps and pseudogaps in a composite model of two-component cuprate

A descriptive interband model of cuprate superconductivity with two-subbands of the defect-component is developed. These are related to "hot" and "cold'' regions of the momentum space. Two pseudogaps appear as the minimal quasiparticle excitations energies. The smaller one transforms with extended doping to the superconducting gap of the itinerant component. At a critical overdoping concentration the larger pseudogap transforms into the defect component superconducting gap. The presence of two pseudogaps in the underdoped state and the extension of the larger pseudogap to overdoping agree with the recent experimental data. The relations between various observed cuprate gaps and other properties are discussed. (C) 2003 Elsevier B.V. All rights reserved.