Desorption of alkali atoms from 4He nanodroplets

Abstract

The dynamics following the photoexcitation of Na and Li atoms located on the surface of helium nanodroplets has been investigated in a joint experimental and theoretical study. Photoelectron spectroscopy has revealed that excitation of the alkali atoms via the (n+1) -> ns transition leads to the desorption of these atoms. The mean kinetic energy of the desorbed atoms, as determined by ion imaging, shows a linear dependence on excitation frequency. These experimental findings are analyzed within a three-dimensional, time-dependent density functional approach for the helium droplet combined with a Bohmian dynamics description of the desorbing atom. This hybrid method reproduces well the key experimental observables. The dependence of the observables on the impurity mass is discussed by comparing the results obtained for the 6Li and 7Li isotopes. The calculations show that the desorption of the excited alkali atom is accompanied by the creation of highly non-linear density waves in the helium droplet that propagate at supersonic velocities.

References in corpus (3)

• Spectroscopy and dynamics in helium nanodroplets
• Excited electron-bubble states in superfluid helium-4: a time-dependent density functional approach
• Absorption spectrum of Ca atoms attached to ${}^4$He nanodroplets

Cited by in corpus (13)

• Photoionizaton of Pure and Doped Helium Nanodroplets
• Density Functional Theory of doped superfluid liquid helium and nanodroplets
• Imaging spectroscopy of rubidium atoms attached to helium nanodroplets
• Ultrafast relaxation of photoexcited superfluid He nanodroplets
• Desorption Dynamics of Heavy Alkali Metal Atoms (Rb, Cs) off the Surface of Helium Nanodroplets
• Electron transfer mediated decay of alkali dimers attached to He nanodroplets
• Time-resolved study of resonant interatomic Coulombic decay in helium nanodroplets
• Dynamics of solvation and desolvation of rubidium attached to He nanodroplets
• Formation and relaxation of RbHe exciplexes on He nanodroplets studied by femtosecond pump and picosecond probe spectroscopy
• Quantum dynamics of Rb atoms desorbing off the surface of He nanodroplets
• First observation of bright solitons in bulk superfluid He-4
• Desorption Dynamics of Rb_2 Molecules off the Surface of Helium Nanodroplets
• Dynamics of photo-excited Cs atoms attached to helium nanodroplets