Resonant Tunneling through Multi-Level and Double Quantum Dots

TL;DR

This paper investigates resonant tunneling in quantum-dot systems with strong Coulomb interactions, revealing a novel triple-peak structure in conductance through theoretical analysis of single and double quantum dots.

Contribution

It introduces a real-time diagrammatic method to analyze spectral density and conductance, uncovering new resonant features in multi-level and double quantum-dot systems.

Findings

Discovery of a triple-peak resonant structure in conductance.

Analysis of spectral density in strongly interacting quantum dots.

Identification of different Kondo-type models based on level spacing.

Abstract

We study resonant tunneling through quantum-dot systems in the presence of strong Coulomb repulsion and coupling to the metallic leads. Motivated by recent experiments we concentrate on (i) a single dot with two energy levels and (ii) a double dot with one level in each dot. Each level is twofold spin-degenerate. Depending on the level spacing these systems are physical realizations of different Kondo-type models. Using a real-time diagrammatic formulation we evaluate the spectral density and the non-linear conductance. The latter shows a novel triple-peak resonant structure.