Electronic Structure and Transition Temperature of the d-p Model

Abstract

The dressed d-electron Green's function of the d-p model is computed self-consistently based on the fluctation-exchange approximation. Using this Green's function and assuming the dx2-y2 symmetry for the momentum dependence of the gap function, we obtain the reasonable superconducting transition temperature Tc in the several cases where the d-(p-)hole number is close to the experimental value of La1.76Sr0.24CuO4 based on NMR/NQR analyses. Using this Green's function, we calculate the d-electron spin susceptibility, which has very sharp incommensurate peaks near Tc for the low frequency as observed in neutron scattering data on La1.86Sr0.14CuO4. The quasi-particle excitation spectrum in the normal state near Tc is also obtained from this Green's function. The energy dispersion fo quasi-particles near the Fermi level is almost flat around the (π/a, 0) point. This electronic structure is due to many-body effects, rather than being induced by band effects.