Fundamental intrinsic lifetimes in semiconductor self-assembled quantum dots

TL;DR

This paper investigates the intrinsic exciton lifetime asymmetry in self-assembled quantum dots, revealing fundamental properties that influence their optical and spin characteristics crucial for quantum information applications.

Contribution

It presents the first theoretical and experimental analysis of exciton lifetime asymmetry in quantum dots, linking it to fundamental QD properties and external influences.

Findings

Intrinsic lifetimes and asymmetry are fundamental to QD properties.

Lifetime asymmetry bounds extrinsic lifetime differences and polarization.

The study provides a basis for understanding QD behavior under external forces.

Abstract

The self-assembled quantum dots (QDs) provide an ideal platform for realization of quantum information technology because it provides on demand single photons, entangled photon pairs from biexciton cascade pro- cess, single spin qubits, and so on. The fine structure splitting (FSS) of exciton is a fundamental property of QDs for thees applications. From the symmetry point of view, since the two bright exciton states belong to two different representations for QDs with C2v symmetry, they should not only have different energies, but also have different lifetimes, which is termed exciton lifetime asymmetry. In contrast to extensively studied FSS, the investigation of the exciton lifetime asymmetry is still missed in literature. In this work, we carried out the first investigation of the exciton lifetime asymmetry in self-assembled QDs and presented a theory to deduce lifetime asymmetry indirectly from measurable qualities of QDs. We further revealed that intrinsic lifetimes and their asymmetry are fundamental quantities of QDs, which determine the bound of the extrinsic lifetime asymmetries, polarization angles, FSSs, and their evolution under uniaxial external forces. Our findings provide an important basis to deeply understanding properties of QDs.