Imaging dynamically-driven strain at the nanometer-scale using stroboscopic Scanning X-ray Diffraction Microscopy

Phononic manipulation provides a direct route to control diverse materials properties in solid state systems. In materials hosting optically-active defects, strain control near engineered structures is an important path to harnessing the potential of solid-state qubits for quantum information science and nanoscale sensing. While lattice strain can be used both statically and dynamically to tune quantum energy levels and engineer hybrid system responses, the direct, independent observation of in-situ nanoscale strain fields induced near quantum defects remains challenging. We report the development of a stroboscopic Scanning X-ray Diffraction Microscopy (s-SXDM) imaging approach for investigating dynamic strain in 4H-SiC, which hosts vacancy related spin defects for quantum sensing and information. This approach uses nano-focused X-ray photon pulses synchronized to a surface acoustic wave (SAW) launcher, in order achieve static time domain and phase sensitive Bragg diffraction imaging with nanoscale spatial resolution near an engineered acoustic-scattering object. We use this technique to simultaneously map near-surface microstructures and acoustically induced lattice curvatures generated by interdigitated transducers fabricated on 4H-SiC as well as corroborate the images with the photoluminescence response of optically-active defect in the SiC, sensitive to local piezoelectric effects. The nanofocused diffraction patterns, stroboscopically varying in time, are analyzed to reveal micro-radian dynamic curvature oscillations trapped near a model structural defect etched into the SiC. This technique yields 0.01 pm d-spacing sensitivity and an effective time resolution of 100 ps. These results demonstrate a unique route for directly studying local strain induced by acoustically manipulated structures under realistic operating conditions.