Renormalization-group analysis of a spin-1 Kondo dot: Non-equilibrium transport and relaxation dynamics

TL;DR

This paper uses a two-loop renormalization group approach to analyze non-equilibrium transport and relaxation in a spin-1 Kondo quantum dot under magnetic field, revealing additional decay rates and effects of anisotropy.

Contribution

It provides analytic results for magnetic field renormalization, decay rates, and transport properties in a spin-1 Kondo system, extending understanding beyond spin-1/2 cases.

Findings

Three additional decay rates compared to spin-1/2 Kondo dot.

Enhanced broadening of logarithmic features in stationary quantities.

Effect of anisotropic couplings on transport and relaxation.

Abstract

We study non-equilibrium transport through a spin-1 Kondo dot in a local magnetic field. To this end we perform a two-loop renormalization group analysis in the weak-coupling regime yielding analytic results for (i) the renormalized magnetic field and the g-factor, (ii) the time evolution of observables and the relevant decay rates, (iii) the magnetization and anisotropy as well as (iv) the current and differential conductance in the stationary state. In particular, we find that compared to a spin-1/2 Kondo dot there exist three additional decay rates resulting in an enhanced broadening of the logarithmic features observed in stationary quantities. Additionally, we study the effect of anisotropic couplings between reservoir and impurity spin.