Quantum nano-photonics with rare-earth-doped materials*

I present quantum nano-photonic devices based on nanophotonic resonators
coupled to rare-earth-ions in crystals. The rare-earth ions exhibit long coherence
times on optical and microwave transitions, which makes them suitable for various
quantum light-matter interfaces line quantum memories, single quantum bits and
optical to microwave quantum transducers. We demonstrate on-chip optical
quantum memories based on atomic frequency combs and optically addressable
quantum bits based on single rare-earth ions where the quantum state can be
mapped on Zeeman or hyperfine levels with long coherence time. Our solid-state
nano-photonic quantum light-matter interfaces can be integrated with other chip-
scale photon source and detector devices for multiplexed quantum and classical
information processing at the nodes of quantum networks.