Coupling of Surface and Volume Dipole Oscillations in C-60 Molecules
arXiv:0710.2749 · doi:10.1142/S021830130800963X
Abstract
We first give a short review of the ``local-current approximation'' (LCA), derived from a general variation principle, which serves as a semiclassical description of strongly collective excitations in finite fermion systems starting from their quantum-mechanical mean-field ground state. We illustrate it for the example of coupled translational and compressional dipole excitations in metal clusters. We then discuss collective electronic dipole excitations in C molecules (Buckminster fullerenes). We show that the coupling of the pure translational mode (``surface plasmon'') with compressional volume modes in the semiclasscial LCA yields semi-quantitative agreement with microscopic time-dependent density functional (TDLDA) calculations, while both theories yield qualitative agreement with the recent experimental observation of a ``volume plasmon''.
LaTeX, 12 pages, 5 figures (8 *.eps files); Contribution to XIV-th Nuclear Physics Workshop at Kazimierz Dolny, Poland, Sept. 26-29, 2007