An integrated nanophotonic quantum register based on silicon-vacancy spins in diamond

We realize an elementary quantum network node consisting of a silicon-vacancy (SiV) color center inside a diamond nanocavity coupled to a nearby nuclear spin with 100-ms-long coherence times. Specifically, we describe experimental techniques and discuss effects of strain, magnetic field, microwave driving, and spin bath on the properties of this two-qubit register. We then employ these techniques to generate Bell states between the SiV spin and an incident photon as well as between the SiV spin and a nearby nuclear spin. We also discuss control techniques and parameter regimes for utilizing the SiV-nanocavity system as an integrated quantum network node.