Quantum simulation of a spin polarization device in an electron microscope

TL;DR

This paper presents a quantum-mechanical simulation of a proposed electron-beam device that acts as a spin-polarization filter, combining diffraction and spin-orbit coupling techniques to assess its feasibility.

Contribution

It introduces a fully quantum simulation approach to evaluate a novel spin-polarization device for electron microscopes, incorporating spin effects via the multi-slice method with a Pauli term.

Findings

Feasibility of the device under realistic conditions

Limitations due to practical implementation challenges

Insights into optimizing spin-polarization efficiency

Abstract

A proposal for an electron-beam device that can act as an efficient spin-polarization filter has been recently put forward [E. Karimi et al., Phys. Rev. Lett. 108, 044801 (2012)]. 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