Single SiV color centers are fabricated in diamond by ion implantation and detected means confocal microscopy. Antibunching of the fluorescence is demonstrated. Through nitrogen doping the quantum efficiency of single photon generation can be enhanced.
Among promising color centers for single-photon sources in diamond, the negatively charged silicon-vacancy (SiV − ) has 70% of its emission to the zero-phonon line (ZPL), in contrast to the negatively charged nitrogen vacancy (NV − ), which has a broad spectrum. Fabricating single centers of useful defect complexes with high yield and excellent grown-in defect properties by ion implantation has proven to be challenging. We have fabricated bright single SiV − centers by 60-keV focused ion beam implantation and subsequent annealing at 1000 °C with high positioning accuracy and a high yield of 15%.
Silicon-vacancy (SiV) centers in diamond are gaining an increased interest for application, such as in quantum technologies and sensing. Due to the strong luminescence concentrated in its sharp zero-phonon line at room temperature, SiV centers are being investigated as single-photon sources for quantum communication, and also as temperature probes for sensing. Here, we discussed strategies for the fabrication of SiV centers in diamond based on Si-ion implantation followed by thermal activation. SiV color centers in high-quality single crystals have the best optical properties, but polycrystalline micro and nanostructures are interesting for applications in nano-optics. Moreover, we discuss the photoluminescence properties of SiV centers in phosphorous-doped diamond, which are relevant for the creation of electroluminescent devices, and nanophotonics strategies to improve the emission characteristics of the SiV centers. Finally, the optical properties of such centers at room and high temperatures show the robustness of the center and give perspectives for temperature-sensing applications.
The development of material-processing techniques that can be used to generate optical diamond nanostructures containing a single-color center is an important problem in quantum science and technology. In this work, we present the combination of ion implantation and top-down diamond nanofabrication in two scenarios: diamond nanopillars and diamond nanowires. The first device consists of a 'shallow' implant (∼20 nm) to generate nitrogen-vacancy (NV) color centers near the top surface of the diamond crystal prior to device fabrication. Individual NV centers are then mechanically isolated by etching a regular array of nanopillars in the diamond surface. Photon anti-bunching measurements indicate that a high yield (>10%) of the devices contain a single NV center. The second device demonstrates 'deep' (∼1 μm) implantation of individual NV centers into diamond nanowires as a post-processing step. The high single-photon flux of the nanowire geometry, combined with the low background fluorescence of the ultrapure diamond, allowed us to observe sustained photon anti-bunching even at high pump powers.