Electron energy-loss spectroscopy of quasi-two-dimensional crystals: Beyond the energy-loss functions formalism

Abstract

A consistent theory of electron energy-loss spectroscopy (EELS) includes two indispensable elements: (i) electronic response of the target system and (ii) quantum kinematics of probing electrons. While for the bulk materials and their surfaces separating these two aspects and focusing on the former is the usual satisfactory practice (the energy-loss functions formalism), we show that, for quasi-2D crystals, the interplay of the system's electronic response and the details of the probe's motion affects EEL spectra dramatically, and it must be taken into account for the reliable interpretation of the experiment. To this end, we come up with a unified theory which, on the same footing, treats both the long- and short-range scattering, within both the transmission and reflection experimental setups. Our calculations performed for graphene reveal a phenomenon of a strong coupling between the $\pi +\sigma$ plasmon excitation and elastic {\it scattering resonances}. Freed from the conventions of the energy-loss functions formalism, our theory serves as a consistent and systematic means of the understanding of the EELS of quasi-2D materials.

8 pages, 6 figures

References in corpus (6)

• Electric Field Effect in Atomically Thin Carbon Films
• Many-body interactions in quasi-freestanding graphene
• Electronic excitations in quasi-2D crystals: What theoretical quantities are relevant to experiment?
• Scattering resonances in graphene
• Mapping Unoccupied Electronic States of Freestanding Graphene by Angle-Resolved Low-Energy Electron Transmission
• Suppression of electron scattering resonances in graphene by quantum dots

Cited by in corpus (6)

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• Towards atomic-resolution quantum measurements with coherently-shaped free electrons
• Dynamical theory of angle-resolved electron energy loss and gain spectroscopies of phonons and magnons in transmission electron microscopy including multiple scattering effects
• Computational methods for 2D materials modelling
• Superradiant Electron Energy Loss Spectroscopy
• An all-electron product-basis set: application to plasmon anisotropy in simple metals