Electron interference effects in energetic photoelectrons from C$_{60}$@C$_{240}$ probed by the Fourier spectroscopy

The ground state structure of the simplest two-fullerene onion system, the C$_{60}$@C$_{240}$ molecule, is solved in the Kohn-Sham framework of local density approximation (LDA). Calculations are carried out with delocalized carbon valence electrons after modeling the onion ion-core of sixty C$^{4+}$ ions from C$_{60}$ and two hundred and forty of those from C$_{240}$ in a smeared out jellium-type double-shell structure [1,2]. Ionization cross sections of all the levels are then calculated in both independent particle LDA and many-particle time dependent LDA approaches at photon energies above the plasmon resonances. These high-energy results exhibit rich structures of energy dependent oscillations from the quantum interference of electron waves produced at the edges of the fullerene layers. A detailed scrutiny of these structures is conducted by Fourier transforming the spectra to the configuration space [3] that relates the oscillations to the onion geometry.\\[4pt] [1] M.E. Madjet, H.S. Chakraborty, J.-M. Rost, and S.T. Manson, \textit{J. Phys.} B \textbf{41}, 105101 (2008);\\[0pt] [2] M.A. McCune, R. De, M.E. Madjet, H.S. Chakraborty, and S.T. Manson, \textit{J. Phys.} B Fast Track Comm. \textbf{44}, 241002 (2011); [3] M.A. McCune, M.E. Madjet, and H.S. Chakraborty, \textit{Phys. Rev.} A \textbf{80}, 011201 (R) (2009).