Single-Electron Charging and Coulomb Interaction in InAs Self-Assembled Quantum Dot Arrays

TL;DR

This paper investigates single-electron charging and Coulomb interactions in InAs quantum dot arrays using capacitance spectroscopy, combining experimental observations with a theoretical model to understand electron interactions.

Contribution

It introduces a theoretical model for Coulomb interactions in InAs quantum dots and validates it with capacitance spectroscopy experiments, distinguishing inter- and intra-dot effects.

Findings

Observation of sequential single-electron charging

Identification of Coulomb energy smaller than quantum level spacing

Good agreement between model and experimental data

Abstract

Sequential single-electron charging is observed in InAs Self-Assembled Quantum Dots using capacitance spectroscopy. In this system, the Coulomb energy is smaller than the inter-level energy spacings due to the quantum confinement and both effects can be separately identified. A theoretical model is proposed for this system and the capacitance experiments were devised in order to experimentally observe the effects of Coulomb interaction between electrons on the dots. The effects of inter- and intra-dot Coulomb interaction have been observed in the capacitanc e spectra. A good agreement between the proposed model and experiment is achieved.