Charge and spin inhomogeneous phases in the ferromagnetic Kondo lattice model

We study numerically the one-dimensional ferromagnetic Kondo lattice. This model is widely used to describe nickel and manganese perovskites. Due to the competition between double and superexchange, we find a region where the formation of magnetic polarons induces a charge-ordered state. This ordering is present even in the absence of any intersite Coulomb repulsion. There is an insulating gap associated to the charge structure formation. We also study the insulator-metal transition induced by a magnetic field, which removes simultaneously both charge and spin ordering.