Diamond for Quantum Technology Applications

The performance of nitrogen-vacancy (NV) center diamond is dependent on the crystalline properties of the substrate and N-doped epitaxial layer. The crystallinity of the substrate and epi-layer in terms of lattice curvature, extended defect concentration and chemical purity determines the baseline characteristics of the final devices, which have immense potential to impact a variety of magnetic field and electric field sensing applications. These technologies are enabled by the negatively charged NV^- center in diamond which has a spin state that can be optically probed and manipulated. The extreme sensitivity of this spin-state to magnetic fields allows for unprecedented capabilities in magnetic and electric field sensing. In this presentation, we report on the assessment of NV center diamond produced by Great Lakes Crystal Technologies. Samples were synthesized at a variety of conditions to investigate optimum growth conditions. Ensemble NV center dephasing times are correlated with defect characteristics measured using birefringence microscopy and lattice curvature measured by x-ray diffraction mapping. UV-visible and Fourier-transform infrared spectroscopy is used to compare parasitic acceptor-like defects concentrations. Results are reported for samples grown using both natural and isotopically purified carbon sources.