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

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.

Automated summary

We investigate the dynamics of the Kondo effect in a system of two metallic Hubbard chains coupled to a magnetic impurity after a quantum quench. For noninteracting electrons, the charge current across the impurity is determined by a scaling function involving the Kondo time. In the case of interacting electrons, we observe a decrease in the Kondo time with increasing repulsive interaction strength, and the time dependence of the current exhibits characteristics of the Kondo effect in a Luttinger liquid. Our findings emphasize the significance of nonequilibrium dynamics in studying quantum impurities in interacting systems.