Understanding nano- and micro-scale crystal strain in CVD diamond is crucial to the advancement of diamond quantum technologies. In particular, the presence of such strain and its characterization present a challenge to diamond-based quantum sensing and information applications -- as well as for future dark matter detectors where directional information of incoming particles is encoded in crystal strain. Here, we exploit nanofocused scanning X-ray diffraction microscopy to quantitatively measure crystal deformation from defects in diamond with high spatial and strain resolution. Combining information from multiple Bragg angles allows stereoscopic three-dimensional modeling of strain feature geometry; the diffraction results are validated via comparison to optical measurements of the strain tensor based on spin-state-dependent spectroscopy of ensembles of nitrogen vacancy (NV) centers in the diamond. Our results demonstrate both strain and spatial resolution sufficient for directional detection of dark matter via X-ray measurement of crystal strain, and provide a promising tool for diamond growth analysis and improvement of defect-based sensing.
@article{arxiv.2103.08388,
title = {Scanning X-ray Diffraction Microscopy for Diamond Quantum Sensing},
author = {Mason C. Marshall and David F. Phillips and Matthew J. Turner and Mark J. H. Ku and Tao Zhou and Nazar Delegan and F. Joseph Heremans and Martin V. Holt and Ronald L. Walsworth},
journal= {arXiv preprint arXiv:2103.08388},
year = {2022}
}