Channeling Vibrational Energy To Probe the Electronic Density of States in Metal Clusters.

We investigate the electronic density of states (DOS) of isolated neutral cobalt clusters by probing the temperature-modulated population of electronic states through UV photoionization. The temperature is controlled via resonant excitation of lattice vibrations using the free-electron laser FELICE, after which the vibrational and electronic systems equilibrate through the electron-phonon coupling, redistributing the population of electronic states. The data are analyzed by surface photoemission theory, modified to incorporate the realistic DOS.