Section: Archived News Stories

Electron Microscopy: A new spin on electron beams

November 4th, 2010 ›


According to a recent article in Nature Nanotechnology's News & Views section, ideas about angular momentum that have been borrowed from optics could allow the magnetic and spin structures of materials to be studied on atomic scales with electron vortex beams.

We are used to electrons occupying states with quantized spin and orbital angular momenta in atoms, but existing methods for generating high-energy electron beams are very inefficient at either producing or transferring states with well-defined spin and/or orbital angular momentum.  This failure stems from the dominance of the direct Coulomb interaction over the spin-spin and spin-orbit interactions for high-energy electrons. As a consequence, even though electron beams can be focused to subatomic dimensions and used to measure the local composition and bonding of a material, they cannot reveal magnetic and spin information on comparable length scales. However, recent work by groups in Japan1 and Europe2 points the way to filling this gap by showing that it might be possible to measure and manipulate orbital angular momentum on the atomic scale with electron microscopes.

The full article can be read in the November 2010 issue of Nature Nanotechlogy.