Time-resolved Rydberg Dynamics in Molecules

We have developed a general model to investigate the ultrafast dynamics of coherently populated Rydberg states in molecules [1]. Autoionizing Rydberg states are highly excited atomic or molecular states that exhibit asymmetric spectral line shapes due their (i) coupling with decay continua [2] and (ii) correlated decay dynamics in external fields. We validated our numerical model against a recent pump-probe photoemission experiment with CO₂ molecules [3], where neutral ground-state CO₂ was excited to the ndσ_g Henning-sharp and nsσ_g Henning-diffuse Rydberg series by an attosecond XUV pulse train and subsequently ionized in a delayed near-infrared probe pulse to the B²Σᵤ⁺  residual CO₂+ ion continuum. Using Fano parameterization [1] and solving the time-dependent Schrödinger equation, we simulated the buildup and decay of coupled Rydberg-states and measured [3] photoelectron yields as a function of the XUV-IR time delay. Our results provide a robust framework for tracking the relaxation dynamics of Rydberg states in molecular systems and offer insights into ultrafast processes in complex quantum systems.