Coherent Driving of a Quantum System with Modulated Free-Space Electrons

Control of quantum systems typically relies on the interaction with electromagnetic radiation. In this study, we experimentally show that the electromagnetic near-field of a spatially modulated free-space electron beam can be used to drive spin systems, demonstrating free-electron-bound-electron resonant interaction. By periodically deflecting the electron beam of a scanning electron microscope in close proximity to a spin-active solid-state sample, and sweeping the deflection frequency across the spin resonance, we directly observe phase coherent coupling between the electron beam's near-field and the two spin states. This method relies only on classically shaping the electron beams transversal correlations and has the potential to enable coherent control of quantum systems with unprecedented, electron microscopic resolution, opening novel possibilities for advanced spectroscopic tools in nanotechnology.