Size, shape, and strain dependence of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>g</mml:mi></mml:math>factor in self-assembled In(Ga)As quantum dots

Abstract

We have investigated Zeeman splitting in single self-assembled InAs and InGaAs quantum dots experimentally and theoretically. By measuring photoluminescence from single dots, in a wide spectral region, we have obtained the exciton $g$ factors of quantum dots with various photoluminescence energies. We find that the absolute value of the exciton $g$ factors of InAs dots are smaller than those of the InGaAs dots, which differs from the composition dependence expected from that of the bulk ones. The experimentally obtained $g$ factors are compared with calculated ones based on the eight-band $\mathbf{k}∙\mathbf{p}$ model where the influence of strain and the Zeeman effect are included. We find a good agreement between the calculation and the experiment qualitatively and quantitatively. The calculation reproduces the nontrivial composition dependence of the $g$ factor of the quantum dots. In addition, the eight-band model predicts a size and shape dependence of the electron and hole $g$ factors of the pyramidal quantum dots.