Calculation of Δ(k,ω) for a two-dimensional t-J cluster -: art. no. 052513

Using numerical techniques, the diagonal and off-diagonal superconducting one-electron Green's functions are calculated for a two-dimensional t-J model on a periodic 32-site cluster at low doping. From these Green's functions, the momentum and frequency dependence of both the real and the imaginary parts of the pairing gap Delta(k,omega) are extracted. It has d(x)(2)-y(2) symmetry and exhibits omega-dependent structure over a scale of several J. The pairing gap at the gap edge Delta(k,omega=Delta(k)) at the antinode persists down to small J/t values. The frequency- and momentum-dependent renormalized energy and renormalization factor are also calculated.