A new way of producing electron vortex probes for STEM

Abstract

A spiral holographic aperture is used in the condensor plane of a scanning transmission electron microscope to produce a focussed electron vortex probe carrying a topological charge of either $-1,0$ or $+1$. The spiral aperture design has a major advantage over the previously used forked aperture in that the three beams with topological charge $m=-1,0,1$ are not side by side in the specimen plane, but rather on top of each other, focussed at different height. This allows us to have only one selected beam in focus on the sample while the others contribute only to a background signal. In this paper we describe the working principle as well as first experimental results demonstrating atomic resolution HAADF STEM images obtained with electron vortex probes. These results pave the way for atomic resolution magnetic information when combined with electron energy loss spectroscopy.

References in corpus (3)

• Semiclassical Dynamics of Electron Wave Packet States with Phase Vortices
• Atomic scale electron vortices for nanoresearch
• Colliding particles carrying non-zero orbital angular momentum

Cited by in corpus (7)

• Achieving atomic resolution magnetic dichroism by controlling the phase symmetry of an electron probe
• Vacuum Faraday effect for electrons
• Topological analysis of paraxially scattered electron vortex beams
• Quantitative measurement of orbital angular momentum in electron microscopy
• Shaping electron beams for the generation of innovative measurements in the (S)TEM
• On-column 2p bound state with topological charge \pm1 excited by an atomic-size vortex beam in an aberration-corrected scanning transmission electron microscope
• Energy loss spectroscopy of Buckminster C60 with twisted electrons: Influence of orbital angular momentum transfer on plasmon generation