Next Generation Diamond Materials for High-Resolution Quantum Sensors

High quality color centers have been demonstrated at the laboratory level to support a number of exciting quantum technology applications in quantum information and optics, navigation and geoscience probes, and nano-sensing in condensed-matter physics, yet a manufacturable process for creating such color centers has yet to be developed. In the crystalline diamond material system, nitrogen vacancy (NV) centers have been utilized at the laboratory level to create a number of exciting quantum sensor and other quantum technology devices and components, many of which show high levels of performance during room temperature testing and evaluation. A clean, reliable, and reproducible manufacturable process for creating high quality diamond materials with NV centers which are controllably positioned, and which have optimized optical and spin properties is of great interest. The team of Great Lakes Crystal Technologies (GLCT) and its research partner Michigan State University (MSU) will apply and extend MSU’s patented technology in microwave plasma assisted chemical vapor deposition (CVD) technology which GLCT has licensed, in combination with advanced femtosecond laser processing and materials characterization technologies developed at MSU to create ultra-high quality CVD diamond materials with controlled arrays of high performance NV centers which in turn will be used to advance the state of the art in magnetic field sensing. We will begin by synthesizing low strain isotopically purified diamond wafers which contain a thin high concentration layer of delta-doped nitrogen at a controllable distance from the surface. Next, we’ll process the samples using lithography, advanced ion implantation and annealing. Specifically, we will activate a periodic array of NV centers in each wafer, using a femtosecond laser annealing process for one wafer and an electron beam irradiation and annealing process for the other wafer. Lastly, we’ll characterize the wafers using photoluminescence spectroscopy and optically detected magnetic resonance (ODMR) spectroscopy to compare their spectral responses, with the goal of understanding the best approach to take forward into Phase II. The proposed technology has a multitude of potential applications in quantum information and optics, navigation and geoscience probes, and nano-sensing in condensed-matter physics, and could inform many other diamond-based approaches to quantum encryption and quantum computing.