Peculiar rotation of electron vortex beams

T. Schachinger (1, 2) , S. Loeffler (1, 2) , Michael Stoeger-Pollach (2) , Peter Schattschneider (3, 1)

1 Inst. für Festkörperphysik und Univ. Serviceeinrichtung für Elektronenmikroskopie
2 Univ Serv Ctr Transmiss Electron Microscopy
3 MSSMat - Laboratoire de mécanique des sols, structures et matériaux

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 Cony 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 Cony rotations all present in one single convergent electron vortex beam. (C) 2015 Elsevier B.V. All rights reserved.

Domaines: Mécanique des matériaux [physics.class-ph]

T. Schachinger, S. Loeffler, Michael Stoeger-Pollach, Peter Schattschneider. Peculiar rotation of electron vortex beams. Ultramicroscopy, 2015, 158, pp.17-25. ⟨10.1016/j.ultramic.2015.06.004⟩. ⟨hal-01342014⟩