Resolving laser-driven electron dynamics at their natural time and length scales is crucial for understanding and controlling light-induced phenomena. This study demonstrates how ultrafast x-ray diffraction can access fundamental information on laser-driven electronic motion in solids. A method based on subcycle-resolved x-ray-optical wave mixing is proposed, enabling straightforward reconstruction of key properties of strong-field-induced electron dynamics with atomic spatial resolution. This technique provides phases and amplitudes of the spatial Fourier transform of optically-induced charge distributions, their temporal behavior, and the direction of the instantaneous microscopic optically-induced electron current flow. It captures the rich microscopic structures and symmetry features of laser-driven electronic charge and current density distributions.

Daria Popova-Gorelova, Robin Santra