Ground State and Magnetization Process of the One-Dimensional Kondo Lattice

The exact numerical diagonalization of the 1-D Kondo lattice is done to obtain energies and correlation functions of this system. In this system the ground state changes from a ferromagnetic state in the low density limit of conduction electrons to a total spin singlet state for the half-filled conduction band. The main mechanism for the suppression of the total spin for half-filling is the antiferromagnetic correlation between the localized spins of nearest neighbor sites. However, the comparison of energies show that the Kondo effect also plays an important role. Increasing the magnetization of the 1-D Kondo lattice the system changes its nature and behaves as a simple spin system, which is determined only by the RKKY interaction.