Matthew A. McCune

Unique role of orbital angular momentum in subshell-resolved photoionization of C60

We predict that the oscillations in the subshell photoionization of C60 evolve with the orbital angular momentum of the bound electrons such that the structures of the highest and the lowest angular momentum subshell cross sections differ dramatically. The effect results from a decrease in the photoelectron production at the molecular inner edge due to the angular momentum generated repulsion on the electron. Fourier analysis of the cross sections at energies below the carbon K-shell continuum indicates that the effect can be observed by photoelectron spectroscopy. The phenomenon should be generic in the photoionization of nanoparticles containing delocalized electrons.

First prediction of the direct effect of a confined atom on photoionization of the confining fullerene

We predict that the confined atom can qualitatively modify the energetic photoionization of some cage levels, even though these levels are of very dominant fullerene character. The effect imposes strong new oscillations in the cross sections which are forbidden to the ionization of empty fullerenes. Results are presented for the Ar@C60 endofullerene compound.

Photoionization of Endohedral Atoms: Collective, Reflective and Collateral Emissions

The photoionization properties of a fullerene-confined atom differ dramatically from that of an isolated atom. In the low energy region, where the fullerene plasmons are active, the electrons of the confined atom emerge through a collective channel carrying a significant chunk of plasmon with it. The photoelectron angular distribution of the confined atom however shows far lesser impact of the effect. At higher energies, the interference between two single-electron ionization channels, one directly from the atom and another reflected off the fullerene cage, producuces oscillatory cross sections. But for the outermost atomic level, which transfers some electrons to the cage, oscillations are further modulated by the collateral emission from the part of the atomic charge density transferred to the cage. These various modes of emissions are studied for the photoionization of Ar endohedrally confined in C{sub 60}.