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High-Yield Fabrication of Entangled Photon Emitters for Hybrid Quantum Networking Using High-Temperature Droplet Epitaxy
journal contribution
posted on 2017-12-14, 00:00 authored by Francesco Basso
Basset, Sergio Bietti, Marcus Reindl, Luca Esposito, Alexey Fedorov, Daniel Huber, Armando Rastelli, Emiliano Bonera, Rinaldo Trotta, Stefano SanguinettiSeveral semiconductor
quantum dot techniques have been investigated
for the generation of entangled photon pairs. Among the other techniques,
droplet epitaxy enables the control of the shape, size, density, and
emission wavelength of the quantum emitters. However, the fraction
of the entanglement-ready quantum dots that can be fabricated with
this method is still limited to around 5%, and matching the energy
of the entangled photons to atomic transitions (a promising route
toward quantum networking) remains an outstanding challenge. Here,
we overcome these obstacles by introducing a modified approach to
droplet epitaxy on a high symmetry (111)A substrate, where the fundamental
crystallization step is performed at a significantly higher temperature
as compared with previous reports. Our method drastically improves
the yield of entanglement-ready photon sources near the emission wavelength
of interest, which can be as high as 95% due to the low values of
fine structure splitting and radiative lifetime, together with the
reduced exciton dephasing offered by the choice of GaAs/AlGaAs materials.
The quantum dots are designed to emit in the operating spectral region
of Rb-based slow-light media, providing a viable technology for quantum
repeater stations.