Ionization and fragmentation of C60 via multiphoton-multiplasmon excitation

We study the intensity dependence of ionization and fragmentation of buckminsterfullerene (C₆₀) in strong laser fields. Our data provide strong evidence that at intensities ≤10¹⁴ W/cm² these processes occur predominantly via multiphoton excitation of the 20 eV plasmon resonance of C₆₀. At least two plasmons have to be created to initiate fragmentation or multiple ionization.