Deterministic Arrays of Epitaxially Grown Diamond Nanopyramids with Embedded Silicon‐Vacancy Centers

Abstract The negatively charged silicon‐vacancy center (SiV) in diamond is a potential high‐quality source of single‐indistinguishable photons for quantum information processing and quantum electrodynamics applications. However, when embedded in bulk diamond, this emitter suffers from both, relatively low extraction efficiency attributed to total internal reflection as well as nondeterministic location. On the other hand, its implementation in nanodiamonds is impeded by optical dephasing owing to their degraded surface quality. Here a robust and deterministic template‐assisted bottom‐up process for the creation of high‐quality diamond nanopyramids incorporating SiVs is reported. This method employs a predefinition of high‐precision nanopillars by e‐beam lithography and dry etching, and subsequent epitaxial overgrowth during which Si atoms are introduced into diamond. The overgrown layer, including the nanopyramid arrays, is epitaxial as confirmed by comprehensive analyses. This diamond nanopyramid, hosting the SiVs, can pave the way toward efficient localized single‐photon source arrays and potentially outshine nanodiamonds and nanosized structures prepared by a top‐down method. The lateral confinement of the SiVs inside the deterministic nanosized pyramids enables their positioning at the center of cavities and optical structures for enhanced quantum efficiency and light–matter manipulation, and their employment as a system to explore collective coherent interactions between ensembles and confined light.