Measuring the orbital angular momentum of electron beams
Abstract
The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations.
- Publication:
-
Physical Review A
- Pub Date:
- February 2014
- DOI:
- 10.1103/PhysRevA.89.025803
- arXiv:
- arXiv:1401.7211
- Bibcode:
- 2014PhRvA..89b5803G
- Keywords:
-
- 42.50.Tx;
- 03.65.Vf;
- 07.78.+s;
- 41.85.-p;
- Optical angular momentum and its quantum aspects;
- Phases: geometric;
- dynamic or topological;
- Electron positron and ion microscopes;
- electron diffractometers;
- Beam optics;
- Physics - Optics;
- Physics - Instrumentation and Detectors;
- Quantum Physics
- E-Print:
- 5 pages, 4 figurse