Quantum-coherent light-electron interaction in an SEM

TL;DR

This paper demonstrates quantum-coherent light-electron interactions in a scanning electron microscope at low electron energies, opening new avenues for quantum experiments, imaging, and computing with extended optical setups.

Contribution

It is the first to show quantum coherent coupling between electrons and light in a SEM at sub-relativistic energies, enabling larger, more flexible quantum optical experiments.

Findings

Quantum coherent coupling achieved at 10.4 keV electron energy.

SEM allows for larger, more configurable optical interaction zones.

Potential for advanced quantum imaging and computing applications.

Abstract

The last two decades experimentally affirmed the quantum nature of free electron wavepackets by the rapid development of transmission electron microscopes into ultrafast, quantum-coherent systems. In particular, ultrafast electron pulses can be generated and timed to interact with optical near-fields, yielding coherent exchange of the quantized photon energy between the relativistic electron wavepacket and the light field. So far, all experiments have been restricted to the physically-confining bounds of transmission electron microscopes, with their small, millimeter-sized sample chambers. In this work, we show the quantum coherent coupling between electrons and light in a scanning electron microscope, at unprecedentedly low electron energies down to 10.4 keV, so with sub-relativistic electrons. Scanning electron microscopes not only afford the yet-unexplored electron energies from ~0.5 to 30 keV providing optimum light-coupling efficiencies, but they also offer spacious and easily-configurable experimental chambers for extended and cascaded optical set-ups, potentially boasting thousands of photon-electron interaction zones. Our results unleashes the full potential of quantum experiments including electron wavepacket shaping and quantum computing with multiple arithmetic operations and will allow imaging with low-energy electrons and attosecond time resolution.