Orbital angular momentum superposition states in transmission electron microscopy and bichromatic multiphoton ionization

TL;DR

This paper demonstrates methods to generate and control electron orbital angular momentum superposition states using holographic masks in electron microscopy and bichromatic laser pulses in atomic ionization, unifying concepts across fields.

Contribution

It introduces a unified approach to creating and manipulating electron OAM superposition states via holography and multiphoton ionization, highlighting their physical similarities.

Findings

Successful generation of electron OAM superpositions with tailored symmetries

Unified physical framework for holographic and laser-based electron state control

Analysis of topological charge and control mechanisms in electron OAM states

Abstract

The coherent control of electron beams and ultrafast electron wave packets dynamics have attracted significant attention in electron microscopy as well as in atomic physics. In order to unify the conceptual pictures developed in both fields, we demonstrate the generation and manipulation of tailored electron orbital angular momentum (OAM) superposition states either by employing customized holographic diffraction masks in a transmission electron microscope or by atomic multiphoton ionization utilizing pulse-shaper generated carrier-envelope phase stable bichromatic ultrashort laser pulses. Both techniques follow similar physical mechanisms based on Fourier synthesis of quantum mechanical superposition states allowing the preparation of a broad set of electron states with uncommon symmetries. We describe both approaches in a unified picture based on an advanced spatial and spectral double slit and point out important analogies. In addition, we analyze the topological charge and discuss the control mechanisms of the free-electron OAM superposition states. Their generation and manipulation by phase tailoring in transmission electron microscopy and atomic multiphoton ionization is illustrated on a 7-fold rotationally symmetric electron density distribution.