One-dimensional Kondo lattice model studied through numerical diagonalization

The one-dimensional Kondo lattice model is studied by means of the numerical diagonalization method. By using massively parallel computations, we were able to study lattices large enough to obtain convergent results for electron densities n <= 2/3. For such densities, an additional ferromagnetic region is found inside the paramagnetic phase. Also, a region is found where the localized spins participate in the low-energy dynamics together with the conduction electrons, thus resulting in a large Fermi surface. These results are an independent confirmation of previous density matrix renormalization group results.