Calculation of near-field scanning optical images of exciton, charged excition and multiexciton wavefunctions in self-assembled InAs/GaAs quantum dots

TL;DR

This paper calculates near-field optical images of various excitonic states in InAs/GaAs quantum dots, revealing detailed wavefunction structures and transition intensities using advanced computational methods.

Contribution

It introduces a combined empirical pseudopotential and configuration interaction approach to model near-field optical images of excitons in quantum dots, including forbidden transitions.

Findings

Wavefunctions of neutral, biexciton, and charged excitons are characterized.

Forbidden far-field transitions become observable in near-field imaging.

Transition intensities vary with exciton type and polarization.

Abstract

The near-field scanning optical microscopy images of excitonic wavefunctions in self-assembled InAs/GaAs quantum dots are calculated using an empirical pseudopotential method, followed by the configuration interaction (CI) treatment of many-particle effects. We show the wavefunctions of neutral exciton $X^0$ of different polarizations, and compare them to those of the biexciton $XX$ and the charged excitons $X^+$ and $X^-$. We further show that the exciton $X(P_h \to S_e)$ transition which is forbidden in the far-field photoluminescence has comparable intensities to that of $X(S_h \to S_e)$ transition in the near-field photoluminescence .