Influence of the Kondo effect in a non-Fermi liquid system

TL;DR

This paper investigates how the Kondo effect manifests in a non-Fermi liquid system described by a Tomonaga-Luttinger liquid, revealing unique screening behavior and scaling properties influenced by strong correlations.

Contribution

It demonstrates the emergence of a special Kondo effect driven by $2k_F$ spin fluctuations in a non-Fermi liquid, extending understanding beyond traditional Fermi liquid models.

Findings

Presence of a $2k_F$-polarized screening cloud around the impurity.

Thermodynamics resembles the two-channel Kondo model in a Fermi liquid.

Mott transition rescales the Kondo temperature dependence on $J_K$.

Abstract

The Kondo effect in a Tomonaga-Luttinger liquid ($U<<t$) is studied by using the non-Abelian bosonization. The $q=2k_F$ enhanced spin fluctuations generate a special Kondo effect, for any sign of the exchange coupling $J_K$ ($\left|J_K\right|<<U$) with the impurity. Then, unlike in Fermi liquids ($U\to 0$), the presence of a $2k_F$-polarized screening cloud around the impurity favors the occurrence of irrelevant electronic operators with scaling dimension $d=3/2$: the thermodynamics is nearly this of the two-channel Kondo model in a Fermi liquid. The Mott insulating transition does not affect much the ground state, but rescales the power-law dependence of the Kondo temperature on $J_K$.