We show a strong indication of the existence of a large Fermi surface in the
one-dimensional Kondo lattice model. The characteristic wave vector of the
model is found to be kF=(1+ρ)π/2, ρ being the density of the
conduction electrons. This result is at first obtained for a variant of the
model that includes an antiferromagnetic Heisenberg interaction JH between
the local moments. It is then directly observed in the conventional Kondo
lattice (JH=0), in the narrow range of Kondo couplings where the long
distance properties of the model are numerically accessible.Comment: 11 pages, 6 figure