Phase detection of electron vortex beams on structured charge distribution

Abstract

Recent advances in the production of so-called twisted electron (electron vortex) beams with sub-nanometer spot size offer unique opportunities to explore the role of orbital angular momentum (OAM) on electromagnetic microstructures. We address here the interaction between the OAM and an external electric field based on the Aharonov–Casher effect. Taking an inhomogeneous electric field generated by a point charge as an example, we show that the deformation of twisted electron's wavefront is very sensitive to the location and orientation of point charges and can be clearly visualized by interference patterns with a spherical wave. This phase shifting detection provides a high resolution representation for the structure and distribution of charged nanoparticles.