Hole doping and weak quenched disorder effects on the 1D Kondo lattice for ferromagnetic Kondo couplings

Abstract

We investigate the one-dimensional Kondo lattice model (1D KLM) for ferromagnetic Kondo couplings, by using the bosonization method. The ferromagnet ic 2-leg spin ladder and the S=1 antiferromagnet occur as new one-dimensional Kondo insulators, for a half-filled band. First,a very small hole-doping makes the charge sector massless and it can produce, either an incommensurate RKKY interaction or a S=1 ferromagnet according to the strength of the ferromagnetic Kondo coupling. Second, we investigate, the effects of a weak and quenched disorder on these two Kondo insulators, by applying renormalization group methods: the Anderson localization is suppressed only in the context of a strong ferromagnetic Kondo coupling.