A New Mean-Field Theory of the Kondo Resonance at Finite Bias

TL;DR

This paper presents a novel slave-boson mean-field approach to analyze the Kondo effect in quantum dots under finite bias, revealing how the Kondo temperature scales with bias voltage.

Contribution

The study introduces a new mean-field model with multiple slave bosons and pseudo-fermions to better understand the Kondo resonance at finite bias.

Findings

Two resonance peaks aligned with lead chemical potentials.

Kondo temperature scales as min(T*, (T*)^2/V).

Model captures bias-dependent Kondo behavior.

Abstract

We introduce a new slave-boson mean-field treatment of the Kondo effect in a quantum dot attached to the leads, when the bias voltage across the leads is finite. The model employs two slave boson and two pseudo-fermion operators to express the localized electron. The solution of the mean-field equations gives in general two resonance peaks pinned to the chemical potential of each lead. The Kondo temperature is shown to scale as $min(\tstar, (\tstar)^2/V)$, where $\tstar$ is the Kondo temperature at equilibrium, and $V$ is the chemical potential difference of the leads.