Thursday, September 16, 2010

Production and application of electron vortex beams

Production and application of electron vortex beams
http://www.nature.com/nature/journal/v467/n7313/full/nature09366.html

J. Verbeeck1, H. Tian1 & P. Schattschneider2

Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
Institute for Solid State Physics and University Service Centre for Electron Microscopy, Vienna University of Technology, A-1040 Vienna, Austria
Correspondence to: J. Verbeeck1 Email: jo.verbeeck@ua.ac.be

Top of pageAbstract
Vortex beams (also known as beams with a phase singularity) consist of spiralling wavefronts that give rise to angular momentum around the propagation direction. Vortex photon beams are widely used in applications such as optical tweezers to manipulate micrometre-sized particles and in micro-motors to provide angular momentum1, 2, improving channel capacity in optical3 and radio-wave4 information transfer, astrophysics5 and so on6. Very recently, an experimental realization of vortex beams formed of electrons was demonstrated7. Here we describe the creation of vortex electron beams, making use of a versatile holographic reconstruction technique in a transmission electron microscope. This technique is a reproducible method of creating vortex electron beams in a conventional electron microscope. We demonstrate how they may be used in electron energy-loss spectroscopy to detect the magnetic state of materials and describe their properties. Our results show that electron vortex beams hold promise for new applications, in particular for analysing and manipulating nanomaterials, and can be easily produced.

To read this story in full you will need to login or make a payment (see right).

No comments: