Generation of a spin-polarized electron beam by multipole magnetic fields

Ebrahim Karimi; Vincenzo Grillo; Robert W Boyd; Enrico Santamato

doi:10.1016/j.ultramic.2013.12.002

Generation of a spin-polarized electron beam by multipole magnetic fields

Ultramicroscopy. 2014 Mar:138:22-7. doi: 10.1016/j.ultramic.2013.12.002. Epub 2013 Dec 31.

Authors

Ebrahim Karimi¹, Vincenzo Grillo², Robert W Boyd³, Enrico Santamato⁴

Affiliations

¹ Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5. Electronic address: ekarimi@uottawa.ca.
² CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena, Italy.
³ Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5; Institute of Optics, University of Rochester, Rochester, NY 14627, USA.
⁴ Dipartimento di Scienze Fisiche, Università di Napoli "Federico II", Compl. Univ. di Monte S. Angelo, 80126 Napoli, Italy; Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Napoli, Italy.

PMID: 24440895
DOI: 10.1016/j.ultramic.2013.12.002

Abstract

The propagation of an electron beam in the presence of transverse magnetic fields possessing integer topological charges is presented. The spin-magnetic interaction introduces a nonuniform spin precession of the electrons that gains a space-variant geometrical phase in the transverse plane proportional to the field's topological charge, whose handedness depends on the input electron's spin state. A combination of our proposed device with an electron orbital angular momentum sorter can be utilized as a spin-filter of electron beams in a mid-energy range. We examine these two different configurations of a partial spin-filter generator numerically. The results of this analysis could prove useful in the design of an improved electron microscope.

Keywords: Electron vortex beam; Polarized electron beam; Spin-to-orbit conversion.

Publication types

Research Support, Non-U.S. Gov't