Electron correlation resonances in the transport through a single quantum level

TL;DR

This paper theoretically investigates electron correlation effects in transport through a single quantum level, highlighting phenomena like the Kondo effect and Coulomb blockade, and proposes conditions for their experimental observation.

Contribution

It introduces a second-order self-energy method within non-equilibrium Green functions to accurately analyze correlation effects, improving upon previous perturbative approaches.

Findings

Identification of Kondo anomaly in current-voltage characteristics

Observation of Coulomb blockade effects

Conditions for experimental detection in quantum dots

Abstract

Correlation effects in the transport properties of a single quantum level coupled to electron reservoirs are discussed theoretically using a non-equilibrium Green functions approach. Our method is based on the introduction of a second-order self-energy associated with the Coulomb interaction that consistently eliminates the pathologies found in previous perturbative calculations. We present results for the current-voltage characteristic illustrating the different correlation effects that may be found in this system, including the Kondo anomaly and Coulomb blockade. We finally discuss the experimental conditions for the simultaneous observation of these effects in an ultrasmall quantum dot.