An Efficient Two-Port Electron Beam Splitter via Quantum Interaction-Free Measurement

TL;DR

This paper proposes a novel electron beam splitter design based on quantum interaction-free measurement, combining an electron resonator with a weak phase grating to efficiently split electron beams with minimal loss.

Contribution

The paper introduces a new electron beam splitter design utilizing quantum IFM principles, enabling efficient two-port splitting in electron optics.

Findings

The design achieves minimal intensity loss through the aperture due to IFM.

The scattering matrix analysis accounts for inelastic scattering effects.

The approach can be generalized to other quantum systems like photons and neutrons.

Abstract

Semi-transparent mirrors are standard elements in light optics for splitting light beams or creating two versions of the same image. Such mirrors do not exist in electron optics, although they could be beneficial in existing techniques such as electron interferometry and holography and enable novel electron imaging and spectroscopy techniques. We propose a design for an electron beam splitter using the concept of quantum interaction-free measurement (IFM). The design combines an electron resonator with a weak phase grating. Fast switching gates allow electrons to enter and exit the resonator. While in the resonator, the phase grating transfers intensity from the direct beam into one of the weakly diffracted beams at each pass. To make the beam splitter an efficient two-port splitter, the intensity in all other diffracted beams is blocked by an aperture. The IFM principle minimizes the loss of total intensity by this aperture. We use a scattering matrix method to analyze the performance of the beam splitter, including the effects of inelastic scattering in the phase grating. This design can be generalized to beam splitters for not only electrons, but also photons, neutrons, atoms, and other quantum mechanical systems.