Ultrafast studies of the relaxation of photoinduced hot electrons in fullerene and endohedral fullerene molecules are valuable in organic photovoltaics [1]. Also, extreme light confinement through plasmon excitation in these molecules, that are prototypes for families of smaller nanosystems, enables plasmon-induced electronic processes, such as, in catalytic reactions or as controllable nanoscale slow-electron sources [2]. With the possibility of easy production of C60 and with remarkable advances in synthesis methods of endohedral C60 in gas phase, in solution or as thin films [3], these systems have recently caught particular attentions. For instance, they render eminent natural laboratories to probe both the relaxation process upon a mid-UV photon absorption and the giant plasmonic electron emission process upon an extreme-UV photon absorption. The former occurs in a femtosecond timescale due to the importance of the electron-phonon nonadiabatic coupling, while the latter plays out at a much faster attosecond speed due to the dominant collective electronic coherence. I will show results of our recent computational studies of both these processes that elicited novel effects [4, 5]. The relaxation study can inspire ultrafast transient absorption and/or time-resolved photoelectron spectroscopic experiments. The plasmonic emission time delay results, on the other hand, has already been brilliantly tested by attosecond photoemission chronoscopic measurements.
REFERENCES [1] S. Collovini and J. S. Delgado, Sust. En. Fuels 2, 2480 (2018) [2] M.S. Tame et al. Quantum plasmonics. Nat. Phys. 9, 329-340 (2013) [3] A. Popov, Nanostructure Science and Technology Series (Springer) (2017) [4] M. Madjet, E. Ali, M. Carignano, O. Vendrell, and H. S. Chakraborty, Phys. Rev. Lett. 126, 183002 (2021). [5] S. Biswas, A. Trabattoni,...., H.S. Chakraborty, M.F. King, and F. Calegari, (2022) http://arxiv.org/abs/2111.14464