Generation of electron vortex beams with over 1000 orbital angular momentum quanta using a tuneable electrostatic spiral phase plate

TL;DR

This paper demonstrates a MEMS-based electrostatic device capable of generating electron vortex beams with over 1000 units of orbital angular momentum, enabling precise calibration and potential for higher OAM values.

Contribution

Introduction of a tunable electrostatic spiral phase plate for producing high-OAM electron vortex beams with over 1000 quanta.

Findings

Vortex diameter increases linearly with OAM

Device can produce over 1000 OAM quanta

Breakdown voltage limits higher OAM generation

Abstract

We report the use of an electrostatic MEMS-based device to produce high quality electron vortex beams with more than 1000 quanta of orbital angular momentum (OAM). Diffraction and off-axis electron holography experiments are used to show that the diameter of the vortex in the diffraction plane increases linearly with OAM, thereby allowing the angular momentum content of the vortex to be calibrated. The realization of electron vortex beams with even larger values of OAM is currently limited by the breakdown voltage of the device. Potential solutions to overcome this problem are discussed.