Quantum dynamics of Rb atoms desorbing off the surface of He nanodroplets

TL;DR

This study investigates the quantum dynamics of excited rubidium atoms desorbing from helium nanodroplets using femtosecond spectroscopy and quantum simulations, confirming the pseudo-diatomic model and revealing energy partitioning during desorption.

Contribution

It combines experimental femtosecond spectroscopy with quantum wave packet simulations to validate the pseudo-diatomic model for Rb-He droplet interactions at the quantum level.

Findings

Good agreement between experiment and simulation supports the pseudo-diatomic model.

Time-resolved spectra show energy sharing between Rb and helium droplet.

Quantum wave packet dynamics accurately describe the desorption process.

Abstract

The desorption of excited rubidium (Rb) atoms off the surface of helium (He) nanodroplets is studied in detail using femtosecond time-resolved photoion and photoelectron imaging spectroscopy in combination with quantum wave packet simulations. The good agreement of the measured time-dependent velocity distributions with the simulation when exciting the Rb dopant atoms into the 6p-state supports the pseudo-diatomic model (PDM) for the Rb-He droplet interaction, even on the level of quantum wave packet dynamics. Time-resolved photoelectron spectra reveal the partitioning of excitation energy into the dopant and the droplet degrees of freedom.