2024 AIChE Annual Meeting
(271c) Ab Initio Characterization of Thermal and Aqueous Stability of Near-Surface Nitrogen-Vacancy Centers in Diamond
Author
Lee, E. - Presenter, University of Chicago
Quantum sensors that leverage the high sensitivity of quantum systems to their environment can radically improve current sensing technologies, including mass-limited chemical analysis, medical diagnostics, and single-cell biology. Among existing platforms, quantum sensors based on electron spins in nitrogen-vacancy (NV) centers in diamond are especially promising, with several recent studies using NV centers to detect ions and molecules within nanoscale volumes of liquid solvent. However, the charge instabilities of NV centers and their surface-related noises under ambient conditions limit their sensing applications. Here, I present our computational study on the chemical processes of near-surface NV centers in an aqueous environment with varying surface terminations of diamond, using ab initio molecular dynamics and density functional theory calculations at the hybrid level. We show how the presence of water and surface terminations impact the stability of energy levels and the local charge distributions of NV centers. We find that thermal effects and interactions between water and functionalized diamond surfaces contribute significantly to the charge stability of NV centers. We discuss the origin of these phenomena and further identify several candidates for surface terminations that would stabilize near-surface NV centers in the aqueous environment. These findings demonstrate the importance of finite temperature and solvation effects in designing atomic-scale defects in wide-bandgap semiconductors for quantum sensing applications.