Interplay between quantum interference and Kondo effects in nonequilibrium transport through nanoscopic systems

TL;DR

This paper investigates how quantum interference and Kondo effects influence electron transport in nanoscale systems, revealing significant conductance changes and negative differential conductance under various conditions.

Contribution

It introduces a model capturing the interplay between interference and Kondo effects in nonequilibrium transport, applicable to diverse nanostructures.

Findings

Conductance varies by orders of magnitude with doublet level splitting.

Temperature dependence of conductance is significantly affected.

Negative differential conductance observed at finite bias.

Abstract

We calculate the finite temperature and non-equilibrium electric current through systems described generically at low energy by a singlet and \emph{two} spin doublets for $N$ and $N \pm 1$ electrons respectively, coupled asymmetrically to two conducting leads, which allows for destructive interference in the conductance. The model is suitable for studying transport in a great variety of systems such us aromatic molecules, different geometries of quantum dots and rings with applied magnetic flux. As a consequence of the interplay between interference and Kondo effect, we find changes by several orders of magnitude in the values of the conductance and its temperature dependence as the doublet level splitting is changed by some external parameter. The differential conductance at finite bias is negative for some parameters.