Focused Ion Beam fabrication of Janus bimetallic cylinders acting as drift~tube Zernike phase plates

TL;DR

This paper demonstrates the fabrication of Janus bimetallic cylinders using focused ion beam techniques to create drift tube Zernike phase plates for electrons, enabling tunable phase shifts for potential applications in electron microscopy.

Contribution

It introduces a novel fabrication method for bimetallic nanostructures acting as phase plates, with tunable phase shifts based on geometric parameters.

Findings

Bimetallic cylinders induce measurable phase shifts in electron interference.

Phase shifts can be controlled by adjusting the height of the cylinders.

The method enables precise fabrication of electron phase-shifting devices.

Abstract

Modern nanotechnology techniques offer new opportunities for fabricating structures and devices at the micron and sub-micron level. Here, we use focused ion beam techniques to realize drift tube Zernike phase plates for electrons, whose operation is based on the presence of contact potentials in Janus bimetallic cylinders, in a similar manner to the electrostatic Aharonov-Bohm effect in bimetallic wires. We use electron Fraunhofer interference to demonstrate that such bimetallic pillar structures introduce phase shifts that can be tuned to desired values by varying their dimensions, in particular their heights.