Density-of-states-driven anisotropies induced by momentum decoupling in Bi2Sr2CaCu2O8

Momentum decoupling arises when small-q scattering dominates the pairing interaction and implies density-of-states-driven anisotropies in superconductivity. In this scheme we explain puzzling aspects of the anisotropy in Bi2Sr2CaCu2O8, such as the correlation of gap magnitude and visibility of the dip above the gap, the enhancement of anisotropy with temperature, the presence of gap minima away from the Γ-X direction and a gap maximum in the Γ-X direction, the similarity of tunnel and angle-resolved photoemission spectra in the Γ-bar M direction, and the asymmetry in vacuum tunnel spectra where the dip structure is present only at negative sample bias. copyright 1996 The American Physical Society