Fig. 2: MD simulation insight into PL measurement on the interaction between SHI and the diamond lattice.

a Comparison of depth-resolved normalized PL intensity (logarithmic scale) of GR1 defect in sample A (no annealing) and NV⁻ defect in the annealed sample B. b The simulated concentrations of vacancies in the form of isolated vacancies and vacancy clusters along the ion trajectory from electronic energy loss processes according to MD simulations. Based on SRIM, the vacancy-creation rate ranges from 0.34 vacancies nm⁻¹ in the direction with the lowest displacement energy ([100], 37.5 eV) to 0.26 vacancies nm⁻¹ in the direction with the highest displacement energy ([110], 47.6 eV)⁵⁴. c Electronic and nuclear stopping powers along the ion trajectory of 1.1 GeV U ions in diamond (right axis). The left axis shows the contour lines of the initial energy density of 10 and 100 eV/nm³ after ion impact in the electronic subsystem as estimated from the delta-ray dose formulas (See Supplementary Note 4). d Visualization of the MD simulation cells at different depth so that atoms are drawn as gray dots. The arrow on the left shows the ion propagation direction. The right two subfigures show the zoom-in area with defect clusters at 7 and 19 μm depth.