Heterogeneous confinement in laterally coupled InGaAs/GaAs quantum dot molecules under lateral electric fields

TL;DR

This paper investigates how lateral electric fields affect the electronic and optical properties of coupled InGaAs/GaAs quantum dot molecules, revealing unique confinement behaviors of electrons and holes with implications for optoelectronic applications.

Contribution

It introduces a combined atomistic modeling and experimental approach to uncover the heterogeneous confinement phenomena in quantum dot molecules under lateral electric fields.

Findings

Electrons perceive the double-dot as a single object.

Holes distinguish two separate dots.

Heterogeneous confinement impacts optical properties.

Abstract

We study the electronic and optical properties of laterally coupled InGaAs/GaAs quantum dot molecules under lateral electric field. We find that electrons perceive the double-dot structure as a compound single object, while the holes discern two well separated dots. Through a combination of predictive atomistic modeling, detailed morphology studies, and single object micro-photoluminescence measurements, we show that this peculiar confinement results in an unusual heterogeneous behavior of electrons and holes with profound consequences on optical properties.