Quench dynamics of the Kondo effect: transport across an impurity coupled to interacting wires

TL;DR

This paper investigates the real-time evolution of the Kondo effect after a quantum quench in systems with interacting wires, revealing how interactions influence the Kondo time and current dynamics.

Contribution

It introduces an effective field theory approach to analyze the Kondo effect dynamics in interacting wires, highlighting the impact of electron interactions on the Kondo time and current behavior.

Findings

Charge current follows a scaling function involving the Kondo time in noninteracting case.

Kondo time decreases with increasing repulsive interactions.

Impurity magnetization relaxation lacks universal scaling below the Kondo time.

Abstract

We study the real-time dynamics of the Kondo effect after a quantum quench in which a magnetic impurity is coupled to two metallic Hubbard chains. Using an effective field theory approach, we find that for noninteracting electrons the charge current across the impurity is given by a scaling function that involves the Kondo time. In the interacting case, we show that the Kondo time decreases with the strength of the repulsive interaction and the time dependence of the current reveals signatures of the Kondo effect in a Luttinger liquid. In addition, we verify that the relaxation of the impurity magnetization does not exhibit universal scaling behavior in the perturbative regime below the Kondo time. Our results highlight the role of nonequilibrium dynamics as a valuable tool in the study of quantum impurities in interacting systems.