Approaching unity photon collection from NV centers via ultra-precise positioning of nanodiamonds in hybrid nanoantennas

Efficient readout of nitrogen-vacancy (NV) centers in diamonds is crucial for various quantum information technologies. However, achieving high-fidelity, single-shot readout at room temperature remains challenging due to limited photon collection efficiency (CE) and background noise. In this work, we enhance the readout efficiency of NV centers by integrating them into hybrid metal–dielectric bullseye nanoantennas using ultra-precise deterministic positioning. This approach enables highly directional emission while minimizing optical losses, resulting in a measured CE of ∼80% at a numerical aperture (NA) as low as 0.5 and approaching unity for NA > 0.8. This marks a substantial improvement over previous realizations using nanodiamonds, by combining hybrid nanoantennas with precise positioning. Our results mark a substantial advancement toward efficient single-shot readout of NV centers by significantly improving readout fidelity and efficiency in a simple on-chip configuration.