Sub-Atomic Channeling and Vortex Beams in SrTiO$_3$

TL;DR

This paper investigates electron probe behavior in SrTiO$_3$ at the sub-atomic scale, revealing sub-atomic channeling and vortex beam formation, with control via temperature and STEM parameters, advancing nanoscale electron microscopy understanding.

Contribution

It demonstrates the existence of sub-atomic channeling and vortex beams in SrTiO$_3$, and shows how STEM parameters can control these phenomena at the sub-atomic level.

Findings

Reducing temperature enhances sub-atomic channeling.

STEM parameters influence vortex beam properties.

Beam simulations cover various energies and angles.

Abstract

Inspired by recent experimental sub-atomic measurements using analytical aberration-corrected scanning transmission electron microscopes (STEMs), we studied electron probe propagation in crystalline SrTiO$_3$ at the sub-atomic length scale. Here, we report the existence of sub-atomic channeling and the formation of a vortex beam at this scale. The results of beam propagation simulations, which are performed at various crystal temperatures and STEM probe convergence angles (10 to 50 mrad) and beam energies (80 to 300 keV), showed that reducing the ambient temperature can enhance the sub-atomic channeling and that STEM probe parameters can be used to control the vortex beams and adjust their intensity, speed, and area.