1 research outputs found
Solid-state ensemble of highly entangled photon sources at rubidium atomic transitions
Semiconductor InAs/GaAs quantum dots grown by the Stranski-Krastanov method
are among the leading candidates for the deterministic generation of
polarization entangled photon pairs. Despite remarkable progress in the last
twenty years, many challenges still remain for this material, such as the
extremely low yield (<1% quantum dots can emit entangled photons), the low
degree of entanglement, and the large wavelength distribution. Here we show
that, with an emerging family of GaAs/AlGaAs quantum dots grown by droplet
etching and nanohole infilling, it is possible to obtain a large ensemble
(close to 100%) of polarization-entangled photon emitters on a wafer without
any post-growth tuning. Under pulsed resonant two-photon excitation, all
measured quantum dots emit single pairs of entangled photons with ultra-high
purity, high degree of entanglement (fidelity up to F=0.91, with a record high
concurrence C=0.90), and ultra-narrow wavelength distribution at rubidium
transitions. Therefore, a solid-state quantum repeater - among many other key
enabling quantum photonic elements - can be practically implemented with this
new material