Attosecond Momentum-Resolved Resonant Inelastic X-ray Scattering for Imaging Coupled Electron–Hole Dynamics

Improving our understanding of electron dynamics is essential for advancing energy transfer, optoelectronics, light-harvesting systems, and quantum computing. Recent developments in attosecond X-ray sources provide the fundamental possibility of observing these dynamics with atomic-scale resolution. However, linking a time-resolved signal to dynamics is challenging due to the broad bandwidth of an attosecond probe pulse. This makes exploring the capabilities of different attosecond imaging techniques crucial. Here, we propose attosecond momentum-resolved resonant inelastic X-ray scattering as a prominent technique for tracking ultrafast dynamics. We demonstrate that the scattering signal contains information about the instantaneous distribution of charge density across the scattering atoms. To illustrate this, we consider scattering from an α-sexithiophene molecule, in which coupled electron-hole dynamics are excited.