EXACT GROUND STATE OF THE GENERALIZED HUBBARD MODEL FOR A WIDE RANGE OF PARAMETERS

Abstract

We present the exact ground-state wave function and energy of the generalized Hubbard model, subjected to the condition that the number of doubly-occupied sites is conserved for a wide physically relevant range of parameters. For one hole and one doubly-occupied site, the existence of the ferromagnetic ground state is proved which allows one to determine the critical value of the on-site repulsion corresponding to the point of metal–insulator transition.