Measurement of g-factor tensor in a quantum dot and disentanglement of exciton spins

TL;DR

This study uses polarization-resolved magneto-optical measurements on single quantum dots to determine the full g-factor tensor and analyze exciton spin evolution, providing insights into spin dynamics and a scheme to measure electron spin coherence.

Contribution

It introduces a method to measure all elements of electron and hole g-factor tensors in quantum dots and proposes a scheme to disentangle exciton spins for electron spin T2 time measurement.

Findings

Good agreement with exchange and Zeeman model

Enhanced measurement precision via polarization analysis

Proposed scheme for electron spin T2 measurement

Abstract

We perform polarization-resolved magneto-optical measurements on single InAsP quantum dots embedded in an InP nanowire. In order to determine all elements of the electron and hole $g$-factor tensors, we measure in magnetic field with different orientations. The results of these measurements are in good agreement with a model based on exchange terms and Zeeman interaction. In our experiment, polarization analysis delivers a powerful tool that not only significantly increases the precision of the measurements, but also enables us to probe the exciton spin state evolution in magnetic fields. We propose a disentangling scheme of heavy-hole exciton spins enabling a measurement of the electron spin $T_2$ time.