Electron Ptychography is the application of ptychographic reconstruction to STEM data — using 4D-STEM datasets (a convergent beam electron diffraction pattern at each scan position) to computationally reconstruct the specimen with resolution approaching the electron wavelength (~2 pm).

How Does Electron Ptychography Work?

• 4D-STEM: At each scan position, record the full 2D diffraction pattern (not just integrated intensity).
• Overlap: Ensure adjacent probe positions have significant overlap (typically 50-80%).
• Reconstruct: Iterative algorithms recover the complex specimen transmission function.
• Resolution: Has achieved ~0.39 Å resolution — the highest resolution imaging ever demonstrated.

Why It Matters

• Record Resolution: Electron ptychography holds the record for the highest resolution imaging of any technique.
• Light Elements: Phase contrast is sensitive to light elements (H, Li, O) that HAADF cannot see.
• Dose Efficient: Can achieve high resolution at lower electron doses, important for beam-sensitive materials.

Electron Ptychography is the ultimate resolution technique — computationally reconstructing images at resolutions approaching the electron wavelength itself.