Interactions of Nitrogen‐Vacancy Centers in Diamond with Electron Beams: Implications for Quantum Sensing and Photoluminescence Stability

Abstract Nitrogen‐vacancy (NV) photoluminescence (PL) in diamond is fundamental to its function as a color center, underpinning advances in sensing science and quantum technologies. The work herein provides critical insights into the atomistic mechanisms of electron beams interacting with NV centers, which are crucial for advancing robust quantum sensing at the nanoscale and controlling the functional properties of nanodiamonds. NV PL and sensing stability of NV‐rich fluorescent nanodiamonds (FNDs) under electron beam irradiation is probed, across a range of energies (20, 80, 100, and 200 keV) and fluences (≈10 ³ to 10 ⁷ e ⁻ nm ⁻² ). PL intensity, NV charge‐state ratios, and sensing contrast, as monitored via optically detected magnetic resonance (ODMR) and magnetic modulation (MM) of PL, are examined. Results reveal complex mechanisms governing interactions between NV‐centers and fast electrons, dominated by ionization and direct knock‐on (DKO) effects, which allow to establish optimum imaging conditions where FNDs can be imaged with sub‐nanometer resolution while preserving their PL and sensing properties (200 keV, <10 ⁵ e ⁻ nm ⁻² ). This methodology enables controlled, top‐down spatial patterning of diamond PL by selectively deactivating NVs, providing novel routes to patterned NV creation.