Mean-field solution of the Kondo lattice away from half-filling

We consider the usual Kondo-lattice, including a Heisenberg-like antiferrom agnetic exchange between nearest-neighbor localized spins. Using a fermion representation for the spin operators, we decouple both Kondo and Heisenber g interactions introducing two mean-held parameters: one associated with th e local Kondo effect, and the other related to the magnetic correlations be tween localized spins. We have concentrated on the non-magnetic case. For w eak Heisenberg coupling, both mean-field parameters are continuously reduce d as the number of conduction electrons departs from one. When the Heisenbe rg interaction is strong, magnetic-correlations are almost insensitive to b and-filling, while the Kondo effect is strongly depleted away from the half -filled band. (C) 1999 Elsevier Science B.V. All rights reserved.