Experimental Verification of Electron Optic Dichroism

Electron optic dichroism, i.e., the spin-dependent attenuation of electron beams transmitted through the vapor of chiral molecules, was investigated. No transmission asymmetry was found for longitudinally polarized electron beams of opposite helicity passing through enantiomeric camphor vapor. The experiment was carried out at electron energies of 0.9, 4.0, and 5.0 eV with an accuracy much better than ${10}^{-4\mathrm{}}$. Asymmetries up to $1.5\times {10}^{-4\mathrm{}}$, which was clearly above the detection limit, were, however, observed for Yb(hfc${)}_3$, a camphorlike molecule containing an ytterbium atom.