Stabilization of near-surface NV⁰ optical resonances by remote carrier injection

Color centers such as the Nitrogen Vacancy center in diamond (NV) are leading solid-state platforms for nanoscale sensing and quantum communication, owing to their long spin coherence and sharp optical resonances. However, near-surface centers suffer from a reduced spin coherence and spectral instability caused by fluctuating charge traps at the diamond interface. 

Here, we exploit the electric-field sensitivity of the neutral (NV⁰) and negative (NV^-) NV center optical resonances at low temperature to probe and mitigate charge noise. We demonstrate that the injection of carriers microns away from individual NVs can deplete charge traps, leading to stabilization of the NV⁰ optical resonance. This approach provides a practical route to preserve the spectral stability of near-surface color centers, enabling new sensing modalities and scalable color-center-based quantum networks.