Exploring single-photon recoil on free electrons

TL;DR

This paper demonstrates experimental detection of single-photon recoil effects on free electrons using coincidence detection, revealing energy-momentum conservation and opening pathways to study entanglement at the quantum level.

Contribution

It introduces a novel experimental approach for observing single-photon recoil on electrons and investigating electron-photon entanglement in a transmission electron microscope.

Findings

Successful detection of energy-momentum conservation at the single-particle level

Observation of weak signals obscured by non-radiative processes

Potential to explore entanglement in electron-photon pairs

Abstract

Recent advancements in time-resolved electron and photon detection enable novel correlative measurements of electrons and their associated cathodoluminescence (CL) photons within a transmission electron microscope. These studies are pivotal for understanding the underlying physics in coherent CL processes. We present experimental investigations of energy-momentum conservation and the corresponding dispersion relation on the single particle level, achieved through coincidence detection of electron-photon pairs. This not only enables unprecedented clarity in detecting weak signals otherwise obscured by non-radiative processes but also provides a new experimental pathway to investigate momentum-position correlations to explore entanglement within electron-photon pairs.