Single-photon emission from the natural quantum dots in the InAs/GaAs wetting layer

TL;DR

This study demonstrates that quantum dots formed in the InAs/GaAs wetting layer emit single photons, confirmed by antibunching and cascade emission, highlighting their potential for quantum communication applications.

Contribution

It provides the first detailed time-resolved microphotoluminescence analysis of naturally formed quantum dots in the wetting layer, identifying their single-photon emission capabilities.

Findings

Spectrally sharp luminescence lines observed

Antibunching with g^2(0)=0.16 confirms single-photon emission

Biexciton-exciton cascade demonstrates non-classical light emission

Abstract

Time-resolved microphotoluminescence study is presented for quantum dots which are formed in the InAs/GaAs wetting layer. These dots are due to fluctuations of In composition in the wetting layer. They show spectrally sharp luminescence lines with a low spatial density. We identify lines related to neutral exciton and biexciton as well as trions. Exciton emission antibunching (second order correlation value of g^2(0)=0.16) and biexciton-exciton emission cascade prove non-classical emission from the dots and confirm their potential as single photon sources.