Abstract
A proposal for an electron-beam device that can act as an efficient spin-polarization filter has been recently put forward (Karimi et al 2012 Phys. Rev. Lett. 108 044801). It is based on combining the recently developed diffraction technology for imposing orbital angular momentum to the beam with a multipolar Wien filter inducing a sort of artificial non-relativistic spin–orbit coupling. Here we reconsider the proposed device with a fully quantum-mechanical simulation of the electron-beam propagation, based on the well-established multi-slice method, supplemented with a Pauli term for taking into account the spin degree of freedom. Using this upgraded numerical tool, we study the feasibility and practical limitations of the proposed method for spin polarizing a free electron beam.
Highlights
In electron microscopy, the electron spin has been, for a long time, a spectator degree of freedom
We have proposed an experiment based on the use of electron vortex beams, i.e. beams carrying orbital angular momentum (OAM)[ 11]
In this work, we introduce a simulation algorithm derived from the multi-slice method used for simulating electron-matter interaction, which is one of the most powerful tools to calculate dynamical scattering in transmission electron microscopy (TEM) [ 15]
Summary
The electron spin has been, for a long time, a spectator degree of freedom. While the classical spin precesses in presence of a magnetic field, a different phase is associated to each “trajectory” inside the quadrupole This phase, in turn, gives rise to a spin-dependent quantum interference effect in the radial direction, allowing for the electron separation according to their spin along this coordinate. In the present case we limit ourselves to the non-relativistic case, adding the sole Pauli term in the interaction Hamiltonian, while postpone to future work a full evaluation of all the relativistic corrections Based on this approach, we aim to reconsider in greater detail the proposed procedure to create beams of polarized electrons. Particular attention will be given to the polarized intensity in relation to the applied field, to the role of the fringing fields, and to the required emission coherence
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
