Imaging Atoms and Fields at Picometer Scale

This lecture by Prof. David Muller from Cornell University explores the cutting-edge technique of ptychography, enabling direct imaging at an unprecedented resolution of 0.5 Å and below 0.2 Å. The lecture covers the principles of scanning transmission electron microscopy, resolution limits imposed by aberrations and diffraction, and the impact of thermal vibrations on resolution. It delves into the challenges of depth sectioning, the use of Lorentz microscopy, and the potential of electron ptychography in studying magnetic skyrmions and ferroelectric materials. The lecture also discusses the advancements in detectors, the importance of count rates, and the application of ptychography in mapping polarization and strain at high speeds.