Doped Kondo chain, a heavy Luttinger liquid.

Khait, Ilia; Azaria, Patrick; Hubig, Claudius; Schollwöck, Ulrich; Auerbach, Assa · Proc Natl Acad Sci U S A · 2018

basic_science · Level V

Where this comes from

Abstract

The doped 1D Kondo Lattice describes complex competition between itinerant and magnetic ordering. The numerically computed wave vector-dependent charge and spin susceptibilities give insights into its low-energy properties. Similar 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-<i>N</i> approximation, we fit the spin velocity by a density-dependent power law of the Kondo coupling. The differences between the large-<i>N</i> theory and our numerical results are associated with the emergent magnetic Ruderman-Kittel-Kasuya-Yosida interactions.