Vertical-Electrical-Field-lnduced Control of the Exciton Fine Structure Splitting in GaAs Island Quantum Dots for the Generation of Polarization-Entangled Photons

摘要

We report on the polarization-resolved photoluminescence spectroscopy of a single GaAs island quantum dot (QD) formed by the monolayer thickness fluctuation of a GaAs/Al_(0.3)Ga_(0.7)As quantum well and embedded in a Schottky device. By applying a forward vertical electric field between the top metallic contact and the sample substrate we suppress the QD excitonic fine structure splitting to ≈1.5μeV. These results open the door toward the possible generation of visible entangled photon pairs using GaAs island QDs.