Intrinsic electric field effects on few-particle interactions in coupled GaN quantum dots

TL;DR

This paper investigates how intrinsic electric fields influence multi-exciton interactions in coupled GaN/AlN quantum dots, revealing unique effects due to material properties that could benefit quantum information applications.

Contribution

It provides a detailed analysis of Coulomb-correlated few-particle states in GaN quantum dots, highlighting effects of intrinsic electric fields distinct from GaAs-based systems.

Findings

Intrinsic exciton-exciton coupling observed

Strong dependence of oscillator strength on dot height

Large energy shifts for dots with different barriers

Abstract

We study the multi-exciton optical spectrum of vertically coupled GaN/AlN quantum dots with a realistic three-dimensional direct-diagonalization approach for the description of few-particle Coulomb-correlated states. We present a detailed analysis of the fundamental properties of few-particle/exciton interactions peculiar of nitride materials. The giant intrinsic electric fields and the high electron/hole effective masses give rise to different effects compared to GaAs-based quantum dots: intrinsic exciton-exciton coupling, non-molecular character of coupled dot exciton wavefunction, strong dependence of the oscillator strength on the dot height, large ground state energy shift for dots separated by different barriers. Some of these effects make GaN/AlN quantum dots interesting candidates in quantum information processing.