Investigation of High‐Density Nitrogen Vacancy Center Ensembles Created in Electron‐Irradiated and Vacuum‐Annealed Delta‐Doped Layers

The creation of localized ensembles of nitrogen vacancy (NV) centers by nitrogen delta doping of chemical vapor deposition diamond with subsequent irradiation of the delta layer by an electron beam with electron energy of 200 keV and annealing at a temperature of 1200 °C is investigated. The concentration of created NV centers is determined as a function of the irradiation dose, and their spin properties are studied. The creation of 2D ensembles of NV centers with a surface density of ≈2500 μm −2 and spin coherence time T 2 ≈ 33 μs is demonstrated.