Doped Kondo chain - a heavy Luttinger liquid

The doped one dimensional Kondo Lattice describes complex competition between itinerant and magnetic ordering. The numerically computed wave-vector dependent charge and spin susceptibilities give new insights to its low energy properties. Similarly to the prediction of the Large-N approximation, gapless spin and charge modes appear at the large Fermi wave-vector. The highly suppressed spin velocity is a manifestation of ``Heavy'' Luttinger liquid quasiparticles. A low energy hybridization gap is detected at the small (conduction band) Fermi wave-vector. In contrast to the exponential suppression of the Fermi velocity in the Large-N approximation, we fit the spin velocity by a density dependent power law of the Kondo coupling. The differences between the Large-N theory and our numerical results are associated with the emergent magnetic RKKY interactions.