Metallic clusters in strong femtosecond laser pulses

We study the electron response of a Na-9(+) cluster excited by strong femtosecond laser pulses by means of a time-dependent density-functional method. We investigate the full electronic dipolar response and multiphoton ionization processes. A strong correlation between induced electronic dipole oscillations and electron emission is observed, leading to a pronounced resonant enhancement of ionization when using lasers operating at the frequency of the Mie plasmon. We also examine the probabilities for producing differently charged ionic states of the system.