DYNAMICAL MEAN-FIELD THEORY FOR DOPED ANTIFERROMAGNETS

We have generalized the dynamical mean-field theory to study the dopin g dependence of the crossover from antiferromagnetic to short-range or der modeled by an incommensurate spin density wave in the Hubbard mode l. The local self-energy which includes spin fluctuations gives quasip article weights and spectral properties in good agreement with quantum Monte Carlo and exact diagonalization data in two dimensions. The spe ctra at finite doping are characterized by a Mott-Hubbard ''gap'' acco mpanied by a pseudogap induced by the local spin order.