Dark-bright exciton coupling in asymmetric quantum dots

Abstract

Symmetry breaking of the confinement in In(Ga)As quantum dots leads to mixing between the bright and dark exciton states and an increase in the oscillator strength of the dark exciton. We demonstrate here that the change in degree of linear polarization of the bright and dark excitons as a function of applied magnetic field, where both parallel and perpendicular magnetic field components are applied, can be used to quantify the dark-bright coupling. Experimental results for a dot where the coupling is weak and the dark exciton is undetectable in zero applied magnetic field are in good agreement with theoretical simulations based on atomistic calculations reported by M. Zieli\ifmmode \acute{n}\else \'{n}\fi{}ski et al. [Phys. Rev. B 91, 085403 (2015)].