Electron ptychography achieves atomic-resolution limits set by lattice vibrations

TL;DR

This paper demonstrates that electron ptychography can achieve atomic-resolution imaging limited only by atomic vibrations, surpassing traditional electron microscopy resolution constraints.

Contribution

The study introduces a method to overcome lens imperfections and multiple scattering effects, enabling atomic-resolution imaging with electron ptychography in thick samples.

Findings

Achieved instrumental blurring under 20 picometers.

Atomic column widths are limited by thermal vibrations, not imaging system.

Potential for sub-nanometer depth resolution and 3D dopant localization.

Abstract

Transmission electron microscopes use electrons with wavelengths of a few picometers, potentially capable of imaging individual atoms in solids at a resolution ultimately set by the intrinsic size of an atom. Unfortunately, due to imperfections in the imaging lenses and multiple scattering of electrons in the sample, the image resolution reached is 3 to 10 times worse. Here, by inversely solving the multiple scattering problem and overcoming the aberrations of the electron probe using electron ptychography to recover a linear phase response in thick samples, we demonstrate an instrumental blurring of under 20 picometers. The widths of atomic columns in the measured electrostatic potential are now no longer limited by the imaging system, but instead by the thermal fluctuations of the atoms. We also demonstrate that electron ptychography can potentially reach a sub-nanometer depth resolution and locate embedded atomic dopants in all three dimensions with only a single projection measurement.