Topological analysis of paraxially scattered electron vortex beams

TL;DR

This paper explores the topological properties of sub-nanometer electron vortex beams as they elastically scatter through atomic potentials, revealing reduced delocalization and site-dependent vortex splitting, with insights into vortex line structures.

Contribution

It provides a novel topological analysis of electron vortex beams interacting with atomic structures, highlighting vortex line behaviors and symmetry effects.

Findings

Reduced delocalization when centered on atomic columns

Site symmetry influences vortex splitting

Complex vortex line structures with loops and twists

Abstract

We investigate topological aspects of sub-nm electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) Significantly reduced delocalization compared to a similar non-vortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns.