Kondo Effect in the Transport Through a Quantum Dot: Extended Noncrossing Approximation Approach

TL;DR

This paper uses an extended noncrossing approximation method to calculate conductance in a quantum dot modeled by the spin 1/2 Anderson model, successfully matching experimental data and clarifying the conductance behavior.

Contribution

It introduces an extended noncrossing approximation approach for the Anderson model, enabling accurate conductance predictions in quantum dots and aligning with experimental results.

Findings

Good agreement with numerical renormalization group results

Successful fitting of experimental measurements

Conductance explained without considering multilevel effects

Abstract

We calculate the conductance through a single quantum dot coupled to metallic leads, modeled by the spin 1/2 Anderson model. We adopt the finite-U extension of the noncrossing approximation method. Our results are in good agreement with exact numerical renormalization group results both in the high temperature and in the Kondo (low temperature) regime. Thanks to this approach, we were able to fit fairly well recently reported measurements by S. De Franceschi et al. in a quantum dot device. We show that, contrarily to what previously suggested, the conductance of this particular device can be understood within the spin-1/2 Anderson model, in which the effects of the multilevel structure of the dot are neglected.