Ionization mechanisms of C60 molecules irradiated by a short intense 800-nm laser pulse are studied. Angle-resolved photoelectron spectra show above-threshold ionization (ATI) patterns with a low peak contrast and a remarkably smooth angular distribution. The results are interpreted by combining two theoretical models. A time-dependent Schrödinger equation (TDSE) calculation based on the B-spline method that explicitly takes into account the molecular potential mimics the single-active-electron response while a statistical model accounts for the many-electron effects. We show that the latter are responsible for the loss of contrast in the ATI peaks. The smooth angular distribution arises in the TDSE calculation as a result of the high angular momentum of the C60 ground electronic state and therefore is a manifestation of the atomic behavior of the molecule.

Phys. Rev. A

Huismans, Y., Cornier, E., Cauchy, C., Hervieux, P.-A., Gademann, G., Gijsbertsen, A., … Vrakking, M. J. J. (2013). Macro-atom versus many-electron effects in ultrafast ionization of C60. Phys. Rev. A, 88(Article number: 13201), 1–6. doi:10.1103/PhysRevA.88.013201