Selection and jump rules in electronic Raman scattering from GaAs/Al_{x}Ga_{1-x}As artificial atoms

TL;DR

This paper provides a theoretical analysis of electronic Raman scattering in GaAs/AlGaAs artificial atoms, revealing how magnetic fields affect polarization rules and predicting a Raman intensity jump at the band gap, aiding in excitation identification.

Contribution

It introduces a theoretical framework for understanding polarization rule breakdown and intensity jumps in Raman spectra of quantum dots under magnetic fields.

Findings

Polarization selection rules break down with magnetic field.

A Raman intensity jump at the band gap is predicted.

The rules help identify charge or spin excitations.

Abstract

A theoretical description of electronic Raman scattering from GaAs/Al_{x}Ga_{1-x}As artificial atoms under the influence of an external magnetic field is presented. Raman spectra with laser excitation energy in the interval E_{gap}-30 meV to E_{gap} are computed in the polarized and depolarized geometry. The polarization ratios for the collective and single-particle excitations indicate a breakdown of the Raman polarization selection rules once the magnetic field is switched on. A Raman intensity jump rule at the band gap is predicted in our calculations. This rule can be a useful tool for identifying the physical nature (charge or spin) of the electronic excitations in quantum dots in low magnetic fields.