Imprinting the quantum statistics of photons on free electrons

Electrons see the quantum nature of light We know that light is both a wave and a particle, and this duality arises from the classical and quantum nature of electromagnetic excitations. Dahan et al . observed that all experiments to date in which light interacts with free electrons have been described with light considered as a wave (see the Perspective by Carbone). The authors present experimental evidence revealing the quantum nature of the interaction between photons and free electrons. They combine an ultrafast transmission electron microscope with a silicon-photonic nanostructure that confines and strengthens the interaction between the light and the electrons. The “quantum” statistics of the photons are imprints onto the propagating electrons and are seen directly in their energy spectrum. —ISO