Quantum fluctuations and electronic transport through strongly interacting quantum dots

TL;DR

This paper employs the numerical renormalization group method to analyze electronic transport in strongly interacting quantum dots, revealing how quantum fluctuations and the Kondo effect influence conductance across various temperatures and conditions.

Contribution

It introduces a finite temperature NRG approach to accurately compute conductance in quantum dots, including spin-resolved properties and magnetic field effects.

Findings

Conductance matches experimental data for quantum dots.

Quantum fluctuations and Kondo effect significantly alter low-temperature transport.

Quantum dots can act as spin filters under magnetic fields.

Abstract

We study electronic transport through a strongly interacting quantum dot by using the finite temperature extension of Wilson's numerical renormalization group (NRG) method. This allows the linear conductance to be calculated at all temperatures and in particular at very low temperature where quantum fluctuations and the Kondo effect strongly modify the transport. The quantum dot investigated has one active level for transport and is modeled by an Anderson impurity model attached to left and right electron reservoirs. The predictions for the linear conductance are compared to available experimental data for quantum dots in heterostructures. The spin-resolved conductance is calculated as a function of gate voltage, temperature and magnetic field strength and the spin-filtering properties of quantum dots in a magnetic field are described.