  We demonstrate the existence of metallic spin density waves (SDWs) in the
Kondo lattice model on a square lattice for a wide range of parameters by means
of real space dynamical mean field theory. In these SDWs, the spin polarization
as well as the charge density depend on the lattice site and are modulated
along one direction of the square lattice. We show that within this phase of
metallic SDWs the Fermi surface changes from small to large, when the coupling
strength is increased. Furthermore, the transition between the large
Fermi-surface SDW phase and the paramagnetic phase is of second order, while
the transition between the small Fermi-surface SDW phase and the paramagnetic
phase is of first order. A local quantum critical point is thus avoided in our
calculations by undergoing a first order phase transition.
