The pseudogap and photoemission spectra in the attractive Hubbard model

Angle-resolved photoemission spectra are calculated microscopically for the two-dimensional attractive Hubbard model. A system of self-consistent T-matrix equations are solved numerically in the real-time domain. The single-particle spectral function has a two-peak structure resulting from the presence of bound states. The spectral function is suppressed at the chemical potential, leading to a pseudogap-like behaviour. At high temperatures and densities the pseudogap diminishes and finally disappears; these findings are similar to the experimental observations for the cuprates.