Electron spin filter and polarizer in a standing light wave

TL;DR

This paper explores the theoretical possibility of using a standing light wave to create a spin-dependent diffraction and polarization effect on electrons, potentially enabling new spin control techniques.

Contribution

It introduces a theoretical framework for electron spin filtering and polarization using counter-propagating circularly polarized laser beams, including analytical and numerical analysis.

Findings

Demonstrates spin-dependent diffraction in a two-photon Kapitza-Dirac process

Shows spin polarization effects through relativistic quantum simulations

Provides a classification scheme for spin properties in electron-light scattering

Abstract

We demonstrate the theoretical feasibility of spin-dependent diffraction and spin-polarization of an electron in two counter-propagating, circularly polarized laser beams. The spin-dynamics appears in a two-photon process of the Kapitza-Dirac effect in the Bragg regime. We show the spin-dependence of the diffraction process by comparison of the time-evolution of a spin-up and spin-down electron in a relativistic quantum simulation. We further discuss the spin properties of the scattering by studying an analytically approximated solution of the time-evolution matrix. A classification scheme in terms of unitary or non-unitary propagation matrices is used for establishing a generalized and spin-independent description of the spin properties in the diffraction process.