Femtosecond dynamics of electronic `bubblesʹ in solid argon: viewing the inertial response and the bath coherences

The dynamics of non-polar electronic solvation has been studied on a model system consisting of NO-doped solid Ar. Excitation of the lowest Rydberg state A(3sσ) of NO leads to formation of an electronic `bubbleʹ, which has been studied by femtosecond pump–probe spectroscopy and classical Molecular Dynamics simulations. The early time behaviour of the transients is identified as the inertial component of the medium response. This first response is followed by a recurrent low-frequency oscillatory motion of the cage for up to ∼2 ps, indicative of coherence in the bath modes.