Kondo Resonance in Transport Properties of Double Barrier Structure

TL;DR

This paper investigates how the finite width of resonant levels in a double barrier structure influences its thermodynamics and transport properties, revealing a transition between Kondo and paramagnetic regimes with distinctive conductance features.

Contribution

It introduces a model accounting for level delocalization and finite width effects, identifying a transition point affecting conductance behavior in double barrier systems.

Findings

Identification of a fixed energy level where the system transitions from Kondo to paramagnetic regime.

Suppression of conductance around the transition energy with an asymmetric resonance.

Demonstration of the impact of level width on tunneling and thermodynamics in single electron charging regimes.

Abstract

I consider the effect of the finite width of the resonant level on its thermodynamics and tunneling transport properties in the single electron charging regime. The finite width of the levels results from their delocalization with formation of a narrow band due to their mutual overlap. Making use of $1/N$ technique one can show that there is a fixed energy level position at which the system undergoes the transition from the Kondo regime (above this energy) to the paramagnetic regime (below it). The linear bias conductance calculated as a function of the chemical potential turns out to be suppressed all around except for the vicinity of the transition energy where it has an asymmetrical resonant behavior.