InAs/GaAs (211)B quantum dots with negligible FSS for the generation of entangled photons

TL;DR

This paper reports on (211)B InAs/GaAs quantum dots that exhibit negligible fine structure splitting, high quantum efficiency, and single photon emission, making them promising for solid-state entangled photon sources.

Contribution

The study demonstrates that (211)B InAs/GaAs quantum dots have significantly lower fine structure splitting compared to (100) dots, with high oscillator strength and efficient single photon emission.

Findings

Negligible fine structure splitting in (211)B dots

High quantum efficiency at 4 K

Effective single photon emission

Abstract

Polarization-resolved single dot spectroscopy performed on (211)B InAs/GaAs quantum dots reveals that the fine structure splitting of the excitonic levels in these dots is much lower compared to the usual (100)-grown InAs dots. Time-resolved measurements confirm the high oscillator strength of these dots, and thus their good quantum efficiency at 4 K, comparable with that of (100) InAs/GaAs dots. Last, photon correlation measurements demonstrate single photon emission out of the excitonic optical transition of these dots. All these features make this novel dot system very promising for implementing solid-state entangled photon sources.