  The prospect of using the quantum nature of light for secure communication
keeps spurring the search and investigation of suitable sources of
entangled-photons. Semiconductor quantum dots are arguably the most attractive.
They can generate indistinguishable entangled-photons deterministically, and
are compatible with current photonic-integration technologies, a set of
properties not shared by any other entanglement resource. However, as no two
quantum dots are identical, they emit entangled-photons with random energies.
This hinders their exploitation in communication protocols requiring
entangled-states with well-defined energies. Here, we introduce scalable
quantum-dot-based sources of polarization-entangled-photons whose energy can be
controlled via dynamic strain-engineering without degrading the degree of
entanglement of the source. As a test-bench, we interface quantum dots with
clouds of atomic vapours, and we demonstrate slow-entangled-photons from a
single quantum emitter. These results pave the way towards the implementation
of hybrid quantum networks where entanglement is distributed among distant
parties using scalable optoelectronic devices.
