Experimental demonstration of an electrostatic orbital angular momentum sorter for electrons

TL;DR

This paper presents the first experimental electrostatic electron OAM sorter capable of analyzing electron OAM states in microscopes, demonstrating its functionality and current resolution, with plans for future improvements.

Contribution

It introduces the first electrostatic electron OAM sorter and verifies its operation for various OAM states in a transmission electron microscope.

Findings

Successfully demonstrated the electrostatic OAM sorter

Recorded electron OAM spectra with the device

Current resolution of 2 in units of h/bar

Abstract

We report the first experimental demonstration of an electrostatic electron orbital angular momentum (OAM) sorter, which can be used to analyze the OAM states of electrons in a transmission electron microscope. We verify the sorter functionality for several electron beams possessing different superpositions of OAM states, and use it to record the electron beams OAM spectra. Our current electrostatic OAM sorter has an OAM resolution of 2 in the units of h/bar - the reduced Planck constant. It is expected to increase the OAM resolution of the sorter to the optimal resolution of 1 in the future via fine control of the sorting phase elements.