Spin-polarizing interferometric beam splitter for free electrons

TL;DR

This paper proposes a novel interferometric method using laser fields to spin-polarize free electron beams, achieving spin separation akin to a Stern-Gerlach device through quantum entanglement and interference.

Contribution

It introduces a laser-based interferometric setup for spin-polarizing free electrons, demonstrating a new approach that mimics Stern-Gerlach separation without magnetic field gradients.

Findings

Successfully splits electron beams into spin components using laser fields.

Analytical and numerical solutions confirm the effectiveness of the method.

The setup achieves spin separation comparable to traditional Stern-Gerlach experiments.

Abstract

A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam into two portions, with electron spin and momentum being entangled. Afterwards, the partial beams are coherently superposed in an interferometric setup formed by standing laser waves. As a result, the outgoing electron beam is separated into its spin components along the laser magnetic field, which is shown by both analytical and numerical solutions of Pauli's equation. The proposed laser field configuration thus exerts the same effect on free electrons like an ordinary Stern-Gerlach magnet does on atoms.