Optical near-field mapping of excitons and biexcitons in naturally occurring semiconductor quantum dots

TL;DR

This paper models the near-field optical spectra of excitons and biexcitons in natural semiconductor quantum dots, predicting spectral intensities and spatial extensions that align with experimental observations.

Contribution

It introduces a non-local response function approach to analyze near-field spectra of excitonic states in naturally occurring quantum dots.

Findings

Predicted the relative intensity of forbidden excitonic states.

Determined the spatial extension of the ground biexciton state.

Results agree with recent experimental data.

Abstract

We calculate the near-field optical spectra of excitons and biexcitons in semiconductor quantum dots naturally occurring at interface fluctuations in GaAs-based quantum wells, using a non-local description of the response function to a spatially modulated electro-magnetic field. The relative intensity of the lowest, far-field forbidden excitonic states is predicted; the spatial extension of the ground biexciton state is found in agreement with recently published experiments.