Cotunneling drag effect in Coulomb-coupled quantum dots

TL;DR

This paper investigates Coulomb drag in Coulomb-coupled double quantum dots, emphasizing the crucial role of cotunneling in understanding the drag effect through combined experimental and theoretical analysis.

Contribution

It demonstrates the importance of cotunneling mechanisms in Coulomb drag within quantum dot systems, providing new insights into the underlying physics.

Findings

Coulomb drag observed in Coulomb-coupled double quantum dots

Cotunneling identified as essential for accurate understanding of drag behavior

Experimental and theoretical analysis confirms the role of cotunneling

Abstract

In Coulomb drag, a current flowing in one conductor can induce a voltage across an adjacent conductor via the Coulomb interaction. The mechanisms yielding drag effects are not always understood, even though drag effects are sufficiently general to be seen in many low-dimensional systems. In this Letter, we observe Coulomb drag in a Coulomb-coupled double quantum dot (CC-DQD) and, through both experimental and theoretical arguments, identify cotunneling as essential to obtaining a correct qualitative understanding of the drag behavior.