title: Spin-to-orbital angular momentum conversion and spin-polarization filtering in electron beams.
abstract: We propose the design of a space-variant Wien filter for electron beams that induces a spin half-turn and converts the corresponding spin angular momentum variation into orbital angular momentum of the beam itself by exploiting a geometrical phase arising in the spin manipulation. When applied to a spatially coherent input spin-polarized electron beam, such a device can generate an electron vortex beam, carrying orbital angular momentum. When applied to an unpolarized input beam, the proposed device, in combination with a suitable diffraction element, can act as a very effective spin-polarization filter. The same approach can also be applied to neutron or atom beams.
authors.affiliation: Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Complesso Universitario di Monte S Angelo, 80126 Napoli, Italy.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Karimi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Marrucci
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Grillo
authors.forename: Enrico
authors.initials: E
authors.lastname: Santamato