Renormalization-group study of a magnetic impurity in a Luttinger liquid

TL;DR

This paper investigates a generalized Anderson model for magnetic impurities in a one-dimensional interacting electron system, revealing how interactions influence local moment formation, Kondo screening, and scattering regimes through a Coulomb gas mapping.

Contribution

It introduces a Coulomb gas approach to analyze impurity behavior in Luttinger liquids, highlighting nonmonotonic Kondo scales and distinct magnetic regimes due to bulk interactions.

Findings

Local-moment regime expands with stronger repulsive interactions.

Kondo temperature varies nonmonotonically with interaction strength.

Two regimes dominated by backward scattering: magnetic and nonmagnetic.

Abstract

A generalized Anderson model for a magnetic impurity in an interacting one-dimensional electron gas is studied via a mapping onto a classical Coulomb gas. For weak potential scattering, the local-moment parameter regime expands as repulsive bulk interactions become stronger, but the Kondo scale for the quenching of the impurity moment varies nonmonotonically. There also exist two regimes dominated by backward potential scattering: one in which the impurity is nonmagnetic, and another in which an unquenched local moment survives down to very low temperatures.