Patent ID: 8758509

Claim:
A thin plate of synthetic single crystal diamond material, the thin plate of synthetic single crystal diamond material having: a thickness in a range 100 nm to 50 μm; a concentration of negatively charged nitrogen-vacancy defects (NV − ) equal to or greater than 100 ppb (parts-per-billion); a concentration of point defects other than the NV − defects of below 200 ppm (parts-per-million); a total nitrogen concentration equal to or greater than 10 ppm; a concentration of all non-nitrogen point defects equal to or less than 1 ppm; wherein at least one major face of the thin plate of synthetic single crystal diamond material comprises surface termination species which have zero nuclear spin and/or zero electron spin; and wherein the product of the concentration of NV − defects and decoherence time T 2 in the thin plate of synthetic single crystal diamond material is at least 0.1 ppm μs.