Tailoring quantum trajectories for strong-field imaging

Strong-field imaging techniques such as laser-induced electron diffraction (LIED) provide unprecedented combined picometer spatial and attosecond temporal resolution by "self-imaging"a molecular target with its own rescattering electrons. Accessing the rich information contained in these experiments requires the ability to accurately manipulate the dynamics of these electrons-namely, their ionization amplitudes, and times of ionization and rescattering-with attosecond to femtosecond precision. The primary challenge is imposed by the multitude of quantum pathways of the photoelectron, reducing the effective measurement to a small range of energies and providing very limited spatial resolution. Here, we show how this ambiguity can be virtually eliminated by manipulating the rescattering pathways with a tailored laser field. Through combined experimental and theoretical approaches, a phase-controlled two-color laser waveformis shown to facilitate the selection of a specific quantum pathway, allowing a direct mapping between the electron's final momentum and the rescattering time. Integrating attosecond control with Ångstrom-scale resolution could advance ultrafast imaging of field-induced quantum phenomena.