Long-distance quantum communication networks require appropriate interfaces between
matter qubit-based nodes and low-loss photonic quantum channels. We implement a
downconversion quantum interface, where the single photons emitted from a semiconductor
quantum dot at 910 nm are downconverted to 1560 nm using a fiber-coupled periodically
poled lithium niobate waveguide and a 2.2-μm pulsed pump laser. The single-photon
character of the quantum dot emission is preserved during the downconversion process: we …

… We report an ultrafast downconversion quantum interface, where 910-nm single photons
from a quantum dot are downconverted to the 1.5-μm telecom band with sub-10 picosecond
pulses at 2.2-μm, enabling the demonstration of quantum-dot spin-photon entanglement. …
We report an ultrafast, low-noise downconversion quantum interface, in which 910-nm
single photons from a quantum dot are downconverted to the 1.5-μm lowest-loss telecom
band. Moreover, the use of sub-10 picosecond pulses at 2.2-μm provides the necessary …