Here is a comprehensize cartoon describing the effects of electron optical activity for three different cases. The bolt represents a chiral target of fixed handedness.

1. The vertical pink arrow represents a transversely polarized electron beam incident on the chiral target. The pink arrow rotated to an angle Ψ indicates the amount of electron optical rotation experienced by the transverse beam.

2. The red and blue arrows represent right-handed and left-handed longitudinally polarized electrons, respectively, as they impinge on the target. After scattering from the target in the forward direction, they are represented by red and blue spheres, the diameters of which indicate the relative intensities of the emerging beams. This is electron circular dichroism.

3. The green figures represent a case so far not discussed. An unpolarized electron beam (represented by the sphere) scattering from chiral molecules will acquire partial transverse polarization (vertical arrow) as well as a partial longitudinal polarization (arrow in the plane).

Link to Abstract

Archived: January 2020