Scaling and Decoherence in the Out-of-Equilibrium Kondo Model

TL;DR

This paper investigates the out-of-equilibrium Kondo effect in quantum dots under bias, using flow equations to analyze the interplay between Kondo physics and decoherence, revealing regimes dominated by single-channel Kondo behavior.

Contribution

It introduces a perturbative scaling approach with flow equations to study the competition between Kondo effect and decoherence in out-of-equilibrium quantum dots.

Findings

Identification of regimes where single-channel Kondo physics dominates

Development of a framework incorporating both equilibrium and non-equilibrium effects

Analysis of decoherence effects induced by current in quantum dots

Abstract

We study the Kondo effect in quantum dots in an out-of-equilibrium state due to an applied dc-voltage bias. Using the method of infinitesimal unitary transformations (flow equations), we develop a perturbative scaling picture that naturally contains both equilibrium coherent and non-equilibrium decoherence effects. This framework allows one to study the competition between Kondo effect and current-induced decoherence, and it establishes a large regime dominated by single-channel Kondo physics for asymmetrically coupled quantum dots.