Femtosecond photoexcitation dynamics inside a quantum solvent
Bernhard Thaler, Sascha Ranftl, Pascal Heim, Stefan Cesnik, Leonhard Treiber, Ralf Meyer, Andreas W. Hauser, Wolfgang E. Ernst, and Markus Koch
Received: 28th March 18
The observation of chemical reactions on the time scale of the motion of electrons and nuclei has been made possible by lasers with ever shortened pulse lengths. Superfluid helium represents a special solvent that permits the synthesis of novel classes of molecules that have eluded dynamical studies so far. However, photoexcitation inside this quantum solvent triggers a pronounced response of the solvation shell, which is not well understood. Here we present a mechanistic description of the solvent response to photoexcitation of dopant atoms inside helium nanodroplets, obtained from femtosecond pump-probe spectroscopy and time-dependent density functional theory simulations. Part of the excited state electronic energy leads to expansion of the solvation shell within 600 fs, initiating a collective oscillation of the superfliuid helium with a period of (28 +- 1) ps. These coupled electronic and nuclear dynamics will be superimposed on intrinsic photoinduced processes of molecular systems inside helium droplets.
Read in full at arXiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.