The generalized self-consistent field (GSCF) theory for the one-dimensional repulsive Hubbard model at half-filling is examined in the presence of magnetic field h in wide range of interaction strength U / t . The evolution of the energy gap in the presence of magnetc field describes a magnetic crossover from itinerant magnetism of weakly bound electron-hole pairs with k F =π/2 to the localized magnetic regime, with the Bose condensation of local electron-hole pairs ( k F =0).
關聯:
Journal of the Physical Society of Japan 71 Suppl., pp.193-195