Formation and relaxation of RbHe exciplexes on He nanodroplets studied by femtosecond pump and picosecond probe spectroscopy

TL;DR

This study uses femtosecond pump-probe spectroscopy to investigate the formation and vibrational relaxation of RbHe exciplexes on helium nanodroplets, revealing a formation time of about 10 ps and relaxation extending beyond 1 ns.

Contribution

It provides detailed time-resolved insights into the formation and relaxation dynamics of RbHe exciplexes on helium nanodroplets, a novel application of femtosecond spectroscopy.

Findings

Exciplex formation time ~10 ps

Vibrational relaxation extends beyond 1 ns

Indicates an indirect, time-delayed desorption process

Abstract

Vibrationally resolved photoionization spectra of RbHe exciplexes forming on He nanodroplets are recorded using femtosecond pump-probe spectroscopy with amplitude-shaped probe pulses. The time-evolution of the spectra reveals an exciplex formation time ~10ps followed by vibrational relaxation extending up to >1ns. This points to an indirect, time-delayed desorption process of RbHe off the He surface.