Scanning X-ray Diffraction Microscopy for Diamond Quantum Sensing

TL;DR

This paper demonstrates a nanofocused X-ray diffraction microscopy technique to precisely measure and model crystal strain in diamond, enabling advancements in quantum sensing and potential dark matter detection.

Contribution

It introduces a high-resolution, stereoscopic X-ray diffraction method for quantifying and modeling diamond crystal strain, validated against optical NV center measurements.

Findings

High spatial and strain resolution achieved

Validated strain measurements with optical spectroscopy

Potential for directional dark matter detection

Abstract

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.