Charge density waves in partially dielectrized <Emphasis Type="Italic">d</Emphasis>-pairing superconductors

A self-consistent theory has been constructed for describing a superconductor with a d _x ²−y ² charge density wave caused by the appearance of a dielectric gap in antinodal sections of the two-dimensional Fermi surface. The theory explains some key features of high-temperature oxides. In particular, it has been shown that the observed large values of the ratio 2Δ(T = 0)/T _c are associated with the stronger suppression of the critical temperature T _c of the superconducting transition rather than the superconducting gap Δ at low temperatures T under the action of charge density waves. It has been predicted that there can exist two critical temperatures of the appearance and disappearance of the dielectric order parameter Σ(T) in a specific range of bare parameters of the model.