  We study the effects of the Coulomb interaction in the one dimensional Kondo
lattice model on the phase diagram, the static magnetic susceptibility and
electron spin relaxation. We show that onsite Coulomb interaction supports
ferromagnetic order and nearest neighbor Coulomb interaction drives, depending
on the electron filling, either a paramagnetic or ferromagnetic order.
Furthermore we calculate electron quasiparticle life times, which can be
related to electron spin relaxation and decoherence times, and explain their
dependence on the strength of interactions and the electron filling in order to
find the sweet spot of parameters where the relaxation time is maximized. We
find that effective exchange processes between the electrons dominate the spin
relaxation and decoherence rate.
