title: Superconducting gap for a two-leg t-J ladder.
abstract: Single-particle diagonal and off-diagonal Green's functions of a two-leg t-J ladder at 1/8 doping are investigated by exact diagonalizations techniques. A numerically tractable expression for the superconducting gap is proposed and the frequency dependence of the real and imaginary parts of the gap are determined. The role of the low-energy gapped spin modes, whose energies are computed by a (one-step) contractor renormalization procedure, is discussed.
authors.affiliation: Laboratoire de Physique Théorique CNRS-UMR5152, Université Paul Sabatier, F-31062 Toulouse, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Poilblanc
authors.forename: D J
authors.initials: DJ
authors.lastname: Scalapino
authors.forename: Sylvain
authors.initials: S
authors.lastname: Capponi