Anisotropic scattering rates and antiferromagnetic precursor effects in the t-t '-U Hubbard model

We have investigated the evolution of the electronic properties of the t-t' -U Hubbard model with hole doping and temperature. Due to the shape of the Fermi surface, scattering from short wavelength spin fluctuations leads to strongly anisotropic quasi-particle scattering rates at lon temperatures ne ar half-filling. As a consequence, significant variations with momenta near the Fermi surface emerge for the spectral functions and the corresponding ARPES signals. At low doping the inverse lifetime of quasiparticles on the Fermi surface is of order k(B)T varying linearly in temperature fr om energ ies of order t down to a very low energy scale set by the spin fluctuation frequency while at intermediate doping a sub-linear T-dependence is obscrve d. This behavior is possibly relevant for the interpretation of photoemissi on spectra in cuprate superconductors at different hole doping levels.