A distorted-wave approach to the elastic scattering of twisted electrons

TL;DR

This paper develops a distorted wave formalism to accurately model elastic scattering of vortex electrons on atoms, showing that including atomic potential effects significantly alters cross section predictions compared to simpler models.

Contribution

It introduces a new distorted wave approach for vortex electron scattering, accounting for atomic potential effects, which improves upon the plane-wave Born approximation.

Findings

Distorted wave effects increase the predicted cross section magnitude.

Significant differences in cross section shape occur for high-Z targets and low topological charge.

Plane-wave Born approximation can be inaccurate for vortex electron scattering under certain conditions.

Abstract

The elastic scattering of spinless vortex electrons on realistic target atoms has been investigated. In particular, expressions are derived in different approximations for the elastic angular-differential cross sections. We develop a distorted wave formalism that includes the effect of the atomic potential on the impinging vortex electron and compare this to a plane-wave Born approximation without such a distortion. Detailed computations have been performed for elastic scattering of vortex electrons on helium, neon, and argon targets by varying the energy, topological charge, and opening angle. Our results show that the overall magnitude of the cross section increases when the distortion by the bound-state electrons is taken into account. We also show that under certain conditions, such as high-Z targets or projectiles with low values of topological charge, significant differences in cross section shape and magnitude are observed between the distorted-wave and plane-wave Born models. Thus, the plane-wave Born approximation must be used with caution when describing vortex electron collisions.