Desorption dynamics of RbHe exciplexes off He nanodroplets induced by spin-relaxation

Abstract

Doped He nanodroplets are ideal model systems to study the dynamics of elementary photophysical processes in heterogeneous nanosystems. Here we present a combined experimental and theoretical investigation of the formation of free RbHe exciplex molecules from laser-excited Rb-doped He nanodroplets. Upon excitation of a droplet-bound Rb atom to the 5p_3/2²Π_3/2-state, a stable RbHe exciplex forms within about 20 ps. Only due to ²Π_3/2 → ²Π_1/2 spin-relaxation does the RbHe exciplex detach from the He droplet surface with a half life of about 700 ps, given by the spin-relaxation time and the coupling of spin and translational degrees of freedom.