Enhanced energy absorption through dissipation in metal clusters
Abstract The paper investigates the dissipation in the electronic dynamics of metallic clusters using a theoretical description in terms of time-dependent mean-field theory with an extension to include electron-electron collisions beyond mean field in terms of a relaxation-time approximation (RTA). The topic is demonstrated on two examples: first, the damping of the all-dominant surface plasmon mode in metallic clusters becoming manifest in the spectral width of the mode and in its lifetime (when viewed in the time domain), and second, the influence of dissipation on the energy absorption of the cluster from an external laser field. The example of laser excitation reveals a dramatic enhancement of energy absorption because dissipation suppresses significantly induced photon emission which is else-wise a process limiting energy intake. The enhancement effect becomes the more important the longer the duration of the laser pulse.