Chiral specific electron vortex beam spectroscopy

TL;DR

This paper explores how electron vortex beams with orbital angular momentum can be used for chiral-specific spectroscopy, revealing new selection rules and the potential to probe magnetic sublevel transitions in materials.

Contribution

It introduces a theoretical framework for inelastic electron vortex beam interactions with atoms, establishing multipolar selection rules dependent on atomic states and positions.

Findings

Selection rules depend on atomic dynamical state and location.

Electron vortex beams can induce magnetic sublevel transitions.

Potential to probe chiral and magnetic properties using electron beams.

Abstract

Electron vortex beams carry well-defined orbital angular momentum (OAM) about the propagation axis. Such beams are thus characterised by chirality features which make them potentially useful as probes of magnetic and other chiral materials. An analysis of the inelastic processes in which electron vortex beams interact with atoms and which involve OAM exchange is outlined, leading to the multipolar selection rules governing this chiral specific electron vortex beam spectroscopy. Our results show clearly that the selection rules are dependent on the dynamical state and location of the atoms involved. In the most favorable scenario, this form of electron spectroscopy can induce magnetic sublevel transitions which are commonly probed using circularly polarized photon beams.