Achieving both high resolution and high precision in imaging complex nanostructured materials is crucial for quantitative determination of their atomic structure. Conventional scanning transmission electron microscopy (STEM) methods often fail to achieve picometer precision at atomic resolution for weakly scattering or radiation-sensitive samples. This paper demonstrates low-dose, sub-angstrom resolution imaging with picometer precision using mixed-state electron ptychography. Correctly accounting for partial beam coherence is key to high-quality reconstructions. The mixed-state approach offers significant advantages in speed and dose efficiency compared to conventional STEM, achieving up to a fifty-fold dose reduction at the same resolution.

Zhen Chen, Michal Odstrcil, Yi Jiang, Yimo Han, Ming-Hui Chiu, Lain-Jong Li, David A. Muller