SINGLE-PARTICLE SPECTRAL-FUNCTION OF A GENERALIZED HUBBARD-MODEL - METAL-INSULATOR-TRANSITION

A generalized Hubbard model with correlated hoppings is studied at half filling using exact diagonalization methods. For certain values of the hopping parameters our results for several static properties, the Drude weight and the single-particle spectra function, suggest the occurrence of a metal-insulator transition (MIT) at a finite value of the local Coulomb interaction Uc. We identify the regions of the hopping parameters where the MIT is of the Mott type. In these regions, for large U<Uc, we find a ferromagnetic ground state. © 1995 The American Physical Society.