Single-particle-picture breakdown in laterally weakly confining GaAs quantum dots

Abstract

We present a detailed investigation of different excitonic states weakly confined in single GaAs/AlGaAs quantum dots obtained by the Al droplet-etching method. For our analysis we make use of temperature-, polarization-, and magnetic-field-dependent $\ensuremath{\mu}$-photoluminescence measurements, which allow us to identify different excited states of the quantum dot system. Besides that, we present a comprehensive analysis of $g$-factors and diamagnetic coefficients of charged and neutral excitonic states in Voigt and Faraday configuration. Supported by theoretical calculations by the configuration-interaction method, we show that the widely used single-particle Zeeman Hamiltonian cannot be used to extract reliable values of the $g$-factors of the constituent particles from excitonic transition measurements.