Evidence of correlation in spin excitations of few-electron quantum dots

TL;DR

This paper presents inelastic light scattering measurements revealing spin and charge excitations in few-electron quantum dots, highlighting significant correlation effects comparable to exchange interactions.

Contribution

It provides the first detailed experimental and theoretical analysis of spin excitations in nanofabricated quantum dots with few electrons, emphasizing correlation effects.

Findings

Observation of a narrow spin excitation peak

Assignment to intershell triplet-to-singlet mode

Large correlation effects comparable to exchange interactions

Abstract

We report inelastic light scattering measurements of spin and charge excitations in nanofabricated AlGaAs/GaAs quantum dots with few electrons. A narrow spin excitation peak is observed and assigned to the intershell triplet-to-singlet monopole mode of dots with four electrons. Configurationinteraction theory provides precise quantitative interpretations that uncover large correlation effects that are comparable to exchange Coulomb interactions.