Attosecond delay and angular asymmetry in plasmonic photoemission of C$_{60}$

We present a theory-experiment joint study of effects of the giant plasmon resonance of C$_{60}$ on photoionization angular asymmetry, phase and time delay. Phases of ionization amplitudes are utilized to compute Wigner-Smith delays and angular asymmetries of emissions from HOMO and HOMO-1 levels in time-dependent local density approximation (TDLDA) [1, 2], uncovering significant plasmon effects [3]. Electron momentum imaging spectroscopy is used to measure the photoelectron angular distribution asymmetry parameter at the plasmon that agreed well with TDLDA [3]. Preliminary results of our experiments using RABITT pump-probe metrology show promise of attosecond measurements of plasmon-driven delays to complement our predictions. * franck.lepine@univ-lyon1.fr ** himadri@nwmissouri.edu \\[4pt] [1] Madjet et al., JPB 41, 105101 (2008);\\[0pt] [2] Maurat et al., JPB 42, 165105 (2009);\\[0pt] [3] Barillot et al., (in review).