GUTZWILLER APPROACH TO THE 3-BAND HUBBARD-MODEL - THE ANTIFERROMAGNETIC PHASE

We study the antiferromagnetic (AFM) state in the three-band Hubbard m odel on the CuO2 plane by using the variational Monte Carlo method (VM C) and the Gutzwiller approximation (GA). Near half-filling, the VMC e nergy is significantly reduced in the AFM state, and is much lower tha n the GA energy. By comparing the energy of the paramagnetic state wit h that of the AFM state, the phase diagram is determined as a function of the hole concentration and the charge-transfer energy. The AFM sta te is stable against doping in a wide range, and this tendency is more pronounced in the hole-doped case than that in the electron-doped cas e. We also study effects of the direct O-O hopping, and find that the direct hopping suppresses the AFM phase especially in the hole-doped c ase.