Transconductance of a double quantum dot system in the Kondo regime

TL;DR

This paper investigates how the Kondo effect in a double quantum dot system influences transconductance, revealing that voltage on one dot significantly affects current through the other, with scaling analysis showing strong enhancement.

Contribution

It introduces a detailed analysis of transconductance in a double quantum dot system within the Kondo regime, highlighting the impact of inter-dot coupling and voltage effects.

Findings

Voltage on one dot strongly affects current through the other.

Kondo effect enhances transconductance significantly.

Poor Man's scaling reveals the underlying mechanism.

Abstract

We consider a lateral double-dot system in the Coulomb blockade regime with a single spin-1/2 on each dot, mutually coupled by an anti-ferromagnetic exchange interaction. Each of the two dots is contacted by two leads. We demonstrate that the voltage across one of the dots will have a profound influence on the current passing through the other dot. Using Poor Man's scaling, we find that the Kondo-effect can lead to a strong enhancement of this {\it transconductance}.