Temperature insensitive optical alignment of the exciton in nanowire embedded GaN Quantum Dots

TL;DR

This study demonstrates that nanowire embedded GaN/AlN quantum dots maintain stable exciton spin polarization across various temperatures, revealing robust optical alignment suitable for quantum applications.

Contribution

It provides new insights into temperature-insensitive exciton spin dynamics and polarization in nanowire embedded GaN/AlN quantum dots, a novel observation in this material system.

Findings

Exciton spin relaxation is quenched under linearly polarized quasiresonant excitation.

The degree of exciton linear polarization remains temperature insensitive.

Orthogonal linear exciton eigenstates are observed without crystallographic preference.

Abstract

We report on the exciton spin dynamics of nanowire embedded GaN/AlN Quantum Dots (QDs) investigated by time-resolved photoluminescence spectroscopy. Under a linearly polarized quasiresonant excitation we evidence the quenching of the exciton spin relaxation and a temperature insensitive degree of the exciton linear polarization, demonstrating the robustness of the optical alignment of the exciton spin in these nanowire embedded QDs. A detailed examination of the luminescence polarization angular dependence shows orthogonal linear exciton eigenstates with no preferential crystallographic orientation.