1111.3259 (Sophia Lloyd et al.)

Quantised orbital angular momentum transfer and magnetic dichroism in
the interaction of electron vortices with matter    [PDF]

Sophia Lloyd, Mohamed Babiker, Jun Yuan

Following the very recent experimental realisation of electron vortices, we
consider their interaction with matter, in particular the transfer of orbital
angular momentum in the context of electron energy loss spectroscopy, and the
recently observed dichroism in thin film magnetised iron samples. We show here
that orbital angular momentum exchange does indeed occur between electron
vortices and the internal electronic-type motion, as well as center of mass
motion of atoms in the electric dipole approximation. This contrasts with the
case of optical vortices where such transfer only occurs in transitions
involving multipoles higher than the dipole. The physical basis of the observed
dichroism is explained.

View original: http://arxiv.org/abs/1111.3259