Multipole Excitation of Fullerene C$_{60}$ Molecules in a Semi-Classical Model

ORAL

Abstract

The local current approximation (LCA) is introduced and derived from a general variational principle. This approach serves as a semiclassical description of strongly collective excitations in finite fermions systems. Here it is first applied to study the coupling of surface and volume dipole oscillations in the fullerene C60 molecules. The spectrum obtained for the coupling of the pure translational mode with compressional volume modes in the semiclassical LCA shows the close agreement with the experimentally observed spectra. Applying the same approach to the photoionization cross section of C60, we discuss the results of higher multipole resonances of fullerene molecules. The comparison to data obtained from electron scattering experiments reveals the adequacy of the semi-classical approach as well as the collective nature of several high angular momentum resonances. Similar to the results of the dipole case, the coupling of surface and volume Plasmon modes in C60 molecules is seen to shift both peaks slightly towards lower energies.

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Authors

  • Krishna Lamichhane

    University of Nevada, Reno

  • Andreas Bill

    Photonics CoE, Sciprint.org, LLNL, OSU, Imperial College London, General Atomis, UCSD, University of Milan, Instituto Superior Technico, University of Alberta, US Dept. of Agriculture, Agriculture Research Service, Parlier, CA, Dept. of Chemistry, California State University, Fresno, Dept. of Physics, California State University, Fresno, Weizmann Institute of Science, Stanford University, University of Connecticut, Storrs, UC Irvine, University of Missouri-Kansas City, California Institute of Technology, Ulm University, TU Darmstadt, UC Berkeley, GSFC, University of Regenberg, Germany, Lawrence Livermore National Laboratory, Clarendon Laboratory, Oxford, University of California, Los Angeles, Gesellschaft fuer Schwerionenforschung (GSI), Laboratoire pour l'Utilisation des Lasers Intenses, PSFC, MIT, University of California, Santa Barbara, Process Measurements Division, National Institute of Standards and Technology, Gaithersburg, MD, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, Division of Chemistry, California Institute of Technology, Pasadena, CA, Department of Physics, Fars Science and Research Center, Islamic Azad University, Texas A\&M University-Commerce, California State University, Long Beach, Materials Department, University of California Santa Barbara

  • Peter Winkler

    University of Nevada, Reno