Electron and holegfactors in InAs/InAlGaAs self-assembled quantum dots emitting at telecom wavelengths

Abstract

We extend the range of quantum dot (QD) emission energies where electron and hole $g$ factors have been measured to the practically important telecom range. The spin dynamics in ${\text{InAs/In}}_{0.53}{\mathrm{Al}}_{0.24}{\mathrm{Ga}}_{0.23}\mathrm{As}$ self-assembled QDs with emission wavelengths at about 1.6 $\ensuremath{\mu}\mathrm{m}$ grown on InP substrate is investigated by pump-probe Faraday rotation spectroscopy in a magnetic field. Pronounced oscillations on two different frequencies, corresponding to the QD electron and hole spin precessions about the field, are observed from which the corresponding $g$ factors are determined. The electron $g$ factor of about $\ensuremath{-}1.9$ has the largest negative value so far measured for III-V QDs by optical methods. This value, as well as the $g$ factors reported for other III-V QDs, differ from those expected for bulk semiconductors at the same emission energies, and this difference increases significantly for decreasing energies.