Weakening of antiferromagnetic correlations by doping in the 2D Hubbard model Original Research Article

The temperature and doping dependence of the 2D Hubbard model is studied in the intermediate coupling regime (U=4). Strong 2D critical spin fluctuations dominating near half-filling are completely destroyed upon about 14% doping concentration, below which the imaginary part of the self-energy vanishes nearly quadratically in both frequency and temperature, a characteristic feature for the Fermi liquid. As the doping concentration is increased from half-filling, dynamical spin susceptibility shows a change from commensurate to incommensurate structure, leading to a three-peak structure in the spectral function in some region of the Brillouin zone.