Correlation exponent K_rho of the one-dimensional Kondo lattice model

TL;DR

This paper investigates the correlation exponent K_rho in the 1D Kondo lattice model, revealing the necessity of logarithmic corrections for spin correlations and providing insights into the gapless nature of the spin sector in the dimerized phase.

Contribution

It introduces a method to compute K_rho from charge correlations and highlights the importance of logarithmic corrections for spin correlations in the model.

Findings

K_rho varies with electron density and coupling strength

Logarithmic corrections are essential for accurate spin correlation description

The spin sector in the dimerized phase at quarter-filling is gapless

Abstract

We present results for the correlation exponent K_rho of the Tomonaga-Luttinger liquid description of the one-dimensional Kondo lattice as a function of conduction electron density and coupling constant. It is obtained from the first derivative of the Fourier transform of the charge-charge correlation function. We also show that the spin correlation function can only be described in this picture if we include logarithmic corrections, a feature that had been previously overlooked. A consistent description of both charge and spin sectors is then obtained. Finally, we show evidence that the spin sector of the dimerized phase at quarter-filling is gapless.