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

Quantum networks hold the promise of secure communication, guaranteed by fundamental laws of physics. Building such networks, however, requires quantum nodes that can relay this quantum information. Here, the authors address practical considerations necessary for building a quantum network node using silicon-vacancy color centers (SiVs) in diamond. Specifically, they describe improvements in nanophotonic cavity design and fabrication, as well as the roles that strain, spin bath, and heating have in performing spin-photon and spin-spin entanglement experiments with SiVs at 100-mK temperatures.