Charged excitons and biexcitons in laterally coupled InGaAs quantum dots

TL;DR

This study uses atomistic calculations to analyze charged excitons and biexcitons in laterally coupled InGaAs quantum dots, revealing complex spectra and many-body effects influenced by electric fields.

Contribution

It provides detailed theoretical insights into the energy spectra and anticrossings of charged quasiparticles in quantum dot molecules under lateral electric fields.

Findings

Negative trion spectrum shows four anticrossings.

Positive trion spectrum shows two anticrossings.

Many-body effects influence carrier tunneling.

Abstract

We present results of atomistic empirical pseudopotential calculations and configuration interaction for excitons, positive and negative trions (X\pm), positive and negative quartons (X2\pm) and biexcitons. The structure investigated are laterally aligned InGaAs quantum dot molecules embedded in GaAs under a lateral electric field. The rather simple energetic of excitons becomes more complex in the case of charged quasiparticles but remains tractable. The negative trion spectrum shows four anticrossings in the presently available range of fields while the positive trion shows two. The magnitude of the anticrossings reveals many-body effects in the carrier tunneling process that should be experimentally accessible.