Bogoliubov quasiparticle excitations in the two-dimensionalt-Jmodel

Using a proposed numerical technique for calculating anomalous Green’s functions characteristic of superconductivity, we show that the low-lying excitations in a wide parameter and doping region of the two-dimensional t-J model are well described by the picture of dressed Bogoliubov quasiparticles in the BCS pairing theory. The pairing occurs predominantly in the ${\mathit{d}}_{\mathit{x}}^2$-${\mathit{y}}^2$-wave channel and the energy gap has a size ${\mathrm{\Delta }}_{\mathit{d}}$≃0.15J–0.27J between quarter and half fillings. Opening of the superconducting gap in the photoemission and inverse-photoemission spectra is demonstrated.