Coulomb correlated multi-particle polarons

TL;DR

This study theoretically investigates Coulomb correlated multi-particle states in quantum dots, revealing that neglecting exchange interactions aligns calculations with experiments and suggesting phonon emission as a key factor in observed polaronic states.

Contribution

It demonstrates that ignoring exchange interactions yields accurate energies and lifetimes, uncovering polaronic effects and providing insights into Coulomb correlations in quantum dot systems.

Findings

Calculated energies match experimental data when exchange interactions are neglected.

Neglected exchange interactions are likely emitted as acoustic phonons during recombination.

Energy spectra analysis offers measurable insights into Coulomb correlation.

Abstract

The electronic and emission properties of correlated multi-particle states are studied theoretically using ${\bf k}\cdot{\bf p}$ and the configuration interaction methods on a well-known and measured GaAs/AlGaAs quantum dots as a test system. The convergence of the calculated energies and radiative lifetimes of Coulomb correlated exciton, biexciton, positive and negative trions to experimentally observed values is reached when the electron-electron and hole-hole exchange interactions are neglected. That unexpected and striking result uncovers a rich structure of multi-particle states in the studied system, which is further quantitatively compared to published measurements in the literature, obtaining astonishingly good agreement. It is proposed that in real experiments the neglected electron-electron and hole-hole exchange interactions are emitted as acoustic phonons during the radiative recombination of the ground state of complexes, leading to the observation of polaronic multi-particle states. Analysis of their energy spectra provides a direct and measurable insight into the Coulomb correlation, being interesting both on the fundamental level and as possible experimentally tunable property in a wide variety of solid-state systems, in particular associated with quantum computing.