Doped Kondo chain - a heavy Luttinger liquid


  Ilia Khait  ,  Patrick Azaria  ,  Claudius Hubig  ,  Ulrich Schollwoeck  ,  Assa Auerbach  
Physics Department, Technion - Israel Institute of Technology, Haifa, Israel.
Laboratoire de Physique Theorique des Liquide, Universite Pierre et Marie Curie, Paris, France.
Arnold Sommerfeld Center for Theoretical Physics, LMU, Munich, Germany.

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.