# Relativistic quantum dynamics of twisted electron beams in arbitrary electric and magnetic fields

## TL;DR

This paper develops a relativistic quantum framework for twisted electron beams in arbitrary electromagnetic fields, predicting a novel radiative orbital polarization effect that could be experimentally verified.

## Contribution

It introduces a relativistic quantum model for twisted electrons in arbitrary fields and predicts a new orbital polarization effect.

## Key findings

- Prediction of radiative orbital polarization in magnetic fields
- Derivation of Hamiltonian and equations of motion in Foldy-Wouthuysen form
- Proposal for a critical experiment to verify the theory

## Abstract

General relativistic quantum dynamics of twisted (vortex) Dirac particles is constructed. The Hamiltonian and equations of motion in the Foldy-Wouthuysen representation are derived for a twisted relativistic electron in arbitrary electric and magnetic fields. A critical experiment for a verification of the results is proposed. The new important effect of a radiative orbital polarization of a twisted electron beam in a magnetic field resulting in a nonzero average projection of the intrinsic orbital angular momentum on the field direction is predicted.