Voltage-controlled electron-hole interaction in a single quantum dot

TL;DR

This study investigates how a small voltage can control the electron-hole exchange interaction in a single quantum dot, revealing charge-dependent tunability and polarization effects through high-resolution spectroscopy.

Contribution

It demonstrates voltage-controlled switching of electron-hole interaction and polarization analysis in a single quantum dot, advancing understanding of charge-dependent excitonic properties.

Findings

Electron-hole exchange interaction depends on exciton charge.

Interaction can be switched on and off with a small dc voltage.

Polarization properties vary with charge and magnetic field.

Abstract

The ground state of neutral and negatively charged excitons confined to a single self-assembled InGaAs quantum dot is probed in a direct absorption experiment by high resolution laser spectroscopy. We show how the anisotropic electron-hole exchange interaction depends on the exciton charge and demonstrate how the interaction can be switched on and off with a small dc voltage. Furthermore, we report polarization sensitive analysis of the excitonic interband transition in a single quantum dot as a function of charge with and without magnetic field.