Electron spectral density of the half-filled Hubbard model in the atomic limit at finite temperature

We have calculated the spectral function and density of states of half-filled two-dimensional Hubbard model in the Hubbard-I approximation assuming an antiferromagnetic long range order at low temperature and compared results to the QMC data. It occurs that calculated functions are in a qualitative agreement with the QMC one. We have also shown that Neel ordered state dispersion has the similar form to the spin density wave one. (C) Central European Science Journals. All rights reserved.