Disentangling multipole contributions to collective excitations in fullerenes

Abstract

Angular resolved electron energy-loss spectroscopy (EELS) gives access to the momentum and the energy dispersion of electronic excitations and allows to explore the transition from individual to collective excitations. Dimensionality and geometry play thereby a key role. As a prototypical example we analyze theoretically the case of Buckminster fullerene C60 using ab initio calculations based on the time-dependent density-functional theory. Utilizing the non-negative matrix factorization method, multipole contributions to various collective modes are isolated, imaged in real space, and their energy and momentum dependencies are traced. A possible experiment is suggested to access the multipolar excitations selectively via EELS with electron vortex (twisted) beams. Furthermore, we construct an accurate analytical model for the response function. Both the model and the ab initio cross sections are in excellent agreement with recent experimental data.

6 pages, 5 figures

References in corpus (2)

• Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems
• A new way of producing electron vortex probes for STEM

Cited by in corpus (6)

• Effects of exchange-correlation potentials on the density functional description of C_60 versus C_240 photoionization
• A Stern-Gerlach-like approach to electron orbital angular momentum measurement
• Photoionization of multishell fullerenes studied by ab initio and model approaches
• Energy loss spectroscopy of Buckminster C60 with twisted electrons: Influence of orbital angular momentum transfer on plasmon generation
• Femtosecond dynamics of correlated many-body states in C${}_{60}$ fullerenes
• Plasmonic breathing modes in ${\mathrm{C}}_{60}$ molecules -- A quantum hydrodynamic approach