Nesting mechanism for<i>d</i>-symmetry superconductors

Abstract

A nested Fermi surface with nearly parallel orbit segments is found to yield a singlet d-wave superconducitng state at high temperatures for a restricted range of the on-site Coulomb repulsion that avoids the competing spin-density-wave instability. The computed superconducting transition temperature drops dramatically as the nesting vector is decreased, in accord with recent photoemission data on the Bi2212 and Bi2201 cuprates. Superconducting transition temperatures in the 100 K range are produced by the nesting mechanism in the leading order pairing interaction caused by exchange of spin fluctuations.