Fig. 5: Angular dependence of ODMR below saturation.

a ODMR spectra (circles) for defect A at two magnetic field orientations, along the z-axis (red) and in the x–y plane (orange), magnetic field vectors represented in (c). The solid curves are fits to the data using a S = 1 model with D = 25 MHz, E = 5 MHz and the defect D tensor symmetry axis (z′) rotated in the plane of hBN. b The simulated ODMR contrast for defect A through the red plane shown in panel (c). The shaded area represents signal intensity normalised to 1. c Schematic showing the magnetic field orientations (red and orange vectors) for measurements in (a) and (b). The red vector points along z, and the orange points out of the xy plane. d ODMR spectra (circles) for defect E at a series of magnetic field orientations through a plane, shown in panel (f). The solid curves are the fit the S = 1 model with D = 25 MHz, E = 5 MHz and z′ rotated in the hBN plane (e) The simulated ODMR contrast for defect E through the blue plane shown in panel (f). f Schematic showing the magnetic field orientations (blue vectors) for measurements in (d) and (e). The blue vectors point at different angles in zy plane with a projection onto x. The sample orientation is shown in both (c) and (f) but the cartoon image (in zy plane).