Persistent atomic frequency comb based on Zeeman sub-levels of an erbium-doped crystal waveguide

Long-lived sub-levels of the electronic ground-state manifold of rare-earth ions in crystals can be used as atomic population reservoirs for photon echo-based quantum memories. We measure the dynamics of the Zeeman sublevels of erbium ions that are doped into a lithium niobate waveguide, finding population lifetimes at cryogenic temperatures...

Entanglement and nonlocality between disparate solid-state quantum memories mediated by photons

Entangling quantum systems with different characteristics through the exchange of photons is a prerequisite for building future quantum networks. Proving the presence of entanglement between quantum memories for light working at different wavelengths furthers this goal. Here, we report on a series of experiments with a thulium-doped crystal,...

Storage and Reemission of Heralded Telecommunication-Wavelength Photons Using a Crystal Waveguide

Large-scale fiber-based quantum networks will likely employ telecommunication-wavelength photons of around 1550 nm wavelength to exchange quantum information between remote nodes, and quantum memories, ideally operating at the same wavelength, that allow the transmission distances to be increased, as key elements of a quantum repeater....