Spatiotemporal Electron-Beam Focusing through Parallel Interactions with Shaped Optical Fields

Abstract: The ability to modulate free electrons with light has emerged as a powerful tool to produce attosecond electron wavepackets. However, research has so far aimed at the manipulation of the longitudinal wave function component, while the transverse degrees of freedom have primarily been utilized for spatial rather than temporal shaping. Here, we show that the coherent superposition of parallel light-electron interactions in separate spatial zones allows for a simultaneous spatial and temporal compression of a convergent electron wave function, enabling the formation of sub-{\AA}ngstr\"om focal spots of attosecond duration. The proposed approach will facilitate the exploration of previously inaccessible ultrafast atomic-scale phenomena in particular enabling attosecond scanning transmission electron microscopy.