HIGH-FREQUENCY HALL-COEFFICIENT FOR THE 2-DIMENSIONAL HUBBARD-MODEL

We numerically calculate the high-frequency Hall coefficient, R(H), fo r the 2D Hubbard model at small hole-doping near half-filling. In the weak-coupling regime R(H) is electron-like and comparable to its U/t=0 value. In the strong-coupling regime, where the mapping onto the t-J model is justified, R(H) is electron-like with small amplitude in the temperature regimes T > U, T < J, and hole-like in the temperature reg ime J < T < U. Our conclusions are consistent with the picture of a Mo tt transition driven by the divergence of the effective mass as oppose d to the vanishing of the number of charge carriers. This conclusion i s valid in the strong- and weak-coupling regimes.