title: Peculiar rotation of electron vortex beams.
abstract: Standard electron optics predicts Larmor image rotation in the magnetic lens field of a TEM. Introducing the possibility to produce electron vortex beams with quantized orbital angular momentum brought up the question of their rotational dynamics in the presence of a magnetic field. Recently, it has been shown that electron vortex beams can be prepared as free electron Landau states showing peculiar rotational dynamics, including no and cyclotron (double-Larmor) rotation. Additionally very fast Gouy rotation of electron vortex beams has been observed. In this work a model is developed which reveals that the rotational dynamics of electron vortices are a combination of slow Larmor and fast Gouy rotations and that the Landau states naturally occur in the transition region in between the two regimes. This more general picture is confirmed by experimental data showing an extended set of peculiar rotations, including no, cyclotron, Larmor and rapid Gouy rotations all present in one single convergent electron vortex beam.
authors.affiliation: Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria; University Service Centre for Transmission Electron Microscopy, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Wien, Austria. Electronic address: thomas.schachinger@tuwien.ac.at.
authors.forename: T
authors.initials: T
authors.lastname: Schachinger
authors.affiliation: Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria; University Service Centre for Transmission Electron Microscopy, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Löffler
authors.affiliation: University Service Centre for Transmission Electron Microscopy, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Stöger-Pollach
authors.affiliation: Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria; LMSSMat (CNRS UMR 8579) Ecole Centrale Paris, F-92295 Châtenay-Malabry, France.
authors.forename: P
authors.initials: P
authors.lastname: Schattschneider
keywords: Electron vortex beams; Gouy rotation; Landau states; Larmor rotation; Magnetic field; TEM