Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals

Significance Monitoring the real-space motion of electrons directly involved in ultrafast molecular dynamics is a challenging goal, hindered by strong contributions remaining inactive electrons. Molecular quantum coherences can provide direct window into elementary electronic dynamics, but they could not be separately imaged so far. Here, we demonstrate time- and frequency-resolved X-ray diffraction technique, which employ existing stochastic pulses to image coherence contributions. The technique selectively follow relevant identify confined regions covered their motion. It enables readily feasible measurements straightforwardly extended full three-dimensional imaging via electron diffraction.