Many-body dipolar dynamics in two-dimensional monolayers of NV and P1 spin ensembles

We report on the fabrication of a non-interacting, shallow two-dimensional ensemble of NV centers with uniform depth, formed by N-terminated diamond surfaces and subsequent epitaxial CVD growth. Using a specially designed growth chamber, our approach aims to realize an ultimately thin monolayer containing high densities of NV centers (up to ~10¹¹ cm⁻²) together with a strongly-interacting ensemble of P1 centers. Nitrogen atoms at the N-terminated interface are expected to convert into either NV or P1 centers, and DEER measurements are therefore required to quantify residual nitrogen not incorporated into NV. Our goal is to simultaneously achieve high concentrations of both NV and P1 centers; in contrast to earlier N-terminated (111) growth yielding ~10⁹ cm⁻² NV densities, the present growth conditions target significantly higher conversion. In addition, samples containing non-interacting shallow NV ensembles with uniform depth will also be valuable for surface sensing applications.