The Influence of Interference on the Kondo Effect in a Quantum Dot

TL;DR

This paper investigates how interference effects in an Aharanov-Bohm ring influence the Kondo effect in a quantum dot, affecting the Kondo temperature and conductance through analytical and numerical methods.

Contribution

It provides a detailed analysis of the impact of interference on the Kondo effect, including the derivation of the Kondo temperature and conductance modifications due to the ring and electron density.

Findings

Kondo temperature is affected by the Aharanov-Bohm ring and electron density.

Zero-temperature conductance varies with interference effects.

Additional potential scattering term arises at low energies due to particle-hole symmetry breaking.

Abstract

We study the Kondo effect in a model system of a quantum dot embedded in an Aharanov-Bohm ring connected to two leads. By transforming to the scattering basis of the direct inter-lead tunneling, we are able to describe precisely how the Kondo screening of the dot spin occurs. We calculate the Kondo temperature and zero-temperature conductance and find that both are influenced by the Aharanov-Bohm ring as well as the electron density in the leads. We also calculate the form of an additional potential scattering term that arises at low energies due to the breaking of particle-hole symmetry. Many of our results are supported by numerical analysis using the numerical renormalization group.