METAL-INSULATOR-TRANSITION IN THE ONE-DIMENSIONAL KONDO-LATTICE MODEL

We study the usual one-dimensional Kondo lattice model (1D KLM) using the non-Abelian bosonization. At half filling, we obtain a Kondo insul ator with a gap in both charge and spin excitations that varies quite linearly with the Kondo exchange J(K). It consists Of a spin-density g lass state, or a q = pi spin density wave weakly pinned by a nearly an tiferromagnetically ordered spin array. We will study the stability of this Kondo insulator against both quenched disorder and interactions between conduction electrons. Away from half filling, the metallic sys tem now yields a very small spin gap that is equal to the one-impurity Kondo gap T-k((imp)). Unlike the one-impurity Kondo model, we will sh ow that this Kondo phase cannot rule the fixed-point of the 1D KLM, aw ay from half filling. We rather obtain a heavy-fermion metallic state controlled by the energy scale T-coh(proportional to)(T-k((imp)))(2)/t (t is the hopping term) with a quite long-range antiferromagnetic pol arization. [S0163-1829(98)00539-6].