Electromagnetic Vortex Fields, Spin, and Spin-Orbit Interactions in Electron Vortices

摘要

Electron vortices are shown to possess electric and magnetic fields by virtue of their quantized orbital angular momentum and their charge and current density sources. The spatial distributions of these fields are determined for a Bessel electron vortex. It is shown how these fields lead naturally to interactions involving coupling to the spin magnetic moment and spin-orbit interactions which are absent for ordinary electron beams. The orders of magnitude of the effects are estimated here for angstrom scale electron vortices generated within a typical electron microscope.