Fano-Kondo interplay in a side-coupled double quantum dot

TL;DR

This paper explores the interplay between Fano resonances and the Kondo effect in a side-coupled double quantum dot system, revealing how interference suppresses the Kondo resonance and providing both experimental and theoretical insights.

Contribution

It demonstrates the Fano-Kondo interplay in a specific quantum dot setup and offers a theoretical model that qualitatively matches experimental observations.

Findings

Fano resonances observed due to interference effects

Partial suppression of Kondo resonance by Fano interference

Theoretical model reproduces experimental features

Abstract

We investigate low-temperature transport characteristics of a side-coupled double quantum dot where only one of the dots is directly connected to the leads. We observe Fano resonances, which arise from interference between discrete levels in one dot and the Kondo effect, or cotunneling in general, in the other dot, playing the role of a continuum. The Kondo resonance is partially suppressed by destructive Fano interference, reflecting novel Fano-Kondo competition. We also present a theoretical calculation based on the tight-binding model with slave boson mean field approximation, which qualitatively reproduces the experimental findings.