Electron and hole g factors in InAs/InAlGaAs self-assembled quantum dots emitting at telecom wavelengths

TL;DR

This study measures electron and hole g factors in InAs/InAlGaAs quantum dots emitting at telecom wavelengths, revealing significant deviations from bulk semiconductor values and providing insights into spin dynamics relevant for quantum communication.

Contribution

It extends g factor measurements to telecom-range quantum dots and reports the largest negative electron g factor observed in III-V QDs via optical methods.

Findings

Electron g factor of about -1.9 measured

Pronounced spin precession oscillations observed

G factors differ from bulk semiconductor expectations

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 InAs/In$_{0.53}$Al$_{0.24}$Ga$_{0.23}$As self-assembled QDs with emission wavelengths at about 1.6 $\mu$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 $-1.9$ 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.