Experimental and theoretical analyses of strongly polarized photon emission from non-polar InGaN quantum dots

TL;DR

This study combines experimental data and theoretical modeling to analyze the polarization properties of non-polar a-plane InGaN quantum dots, revealing their high polarization degree and potential for quantum cryptography applications.

Contribution

It provides the first comprehensive statistical and theoretical analysis of polarization in a-plane InGaN QDs, highlighting their insensitivity to size and shape variations.

Findings

Average polarization degree of 0.90 with low standard deviation

91% of QDs polarized along the [1-100] axis

High potential for linearly polarized single-photon emission

Abstract

We present a comprehensive investigation of the polarization properties of non-polar a-plane InGaN quantum dots (QDs) and their origin with statistically significant experimental data and rigorous k.p modelling. The unbiased selection and study of 180 individual QDs allow us to compute an average polarization degree of 0.90, with a standard deviation of only 0.08. When coupled with theoretical insights, we show that a-plane InGaN QDs are highly insensitive to size differences, shape anisotropies, and indium content fluctuations. Furthermore, 91% of the studied QDs exhibit a polarization axis along the crystal [1-100] axis, with the other 9% polarized orthogonal to this direction. When coupled with their ability to emit single-photons, a-plane QDs are good candidates for the generation of linearly polarized single-photons, a feature attractive for quantum cryptography protocols.