Subshell orbital-resolved attosecond dynamics of nonadiabatic valence electrons in strong-field ionization and rescattering

Abstract Attosecond electron dynamics in strong laser fields govern fundamental light-matter interactions, yet subshell orbital-resolved ionization and rescattering processes of valence electrons have remained obscured by quantum many-body effects. Here, we present a theoretical breakthrough by combining time-dependent density functional theory (TDDFT) with Bohmian mechanics (BM) analysis (TDDFT-BM) for nonadiabatic treatment of subshell quantum-trajectory-resolved ionization and rescattering processes of many-electron atomic systems in intense laser fields, enabling attosecond-scale tracking of both ionization and rescattering dynamics in nonadiabatic multielectron systems. Angular momentum orientation-resolved BM quantum trajectories manifest an unexpected characteristic phenomenon in ionization and rescattering processes, which 3p±1 electron escapes faster than 3p₀ and 3s electrons, exhibiting an instantaneous intensity-dependent ionization delay, but a rescattering inversion occurs during photoemission, where the more deeply bound 3s electrons and weakly bound 3p₀ electrons return to the core earlier than 3p±1 electrons. This demonstrates that the orbital orientation with the electron density perpendicular to the electric field accelerates ionization but decelerates rescattering, even though the relative ionization probability is small. Our findings not only resolve long-standing puzzles in attosecond quantum dynamics but also establish TDDFT-BM as a transformative tool for controlling electronic motion at its natural timescale.