Magnetic phase diagrams of the generalized spin-one-half Falicov-Kimball model

Abstract

A combination of small-cluster exact-diagonalization calculations and a well-controlled approximative method is used to examine the ground-state phase diagrams of the spin-one-half Falicov-Kimball model extended by the spin-dependent on-site interaction ($J$) between localized spins and itinerant ($d$) electrons, as well as by external magnetic field ($h$). Both the magnetic ordering and metamagnetic transitions are analysed as functions of $h$ and the number of itinerant electrons ($N_d$) at selected $J$. Various magnetic superstructures including axial and diagonal spin stripes are observed for nonzero values of $J$ and $h$. Moreover, it is shown that increasing $h$ strongly stabilizes the fully and partially polarized states, while the non polarized state is reduced.