Speaker
Description
Swift electrons in electron microscopy provide a unique tool for probing and manipulating nanoscale
materials, enabling access to electronic, optical, and collective excitations through techniques
such as electron energy-loss spectroscopy and cathodoluminescence. A detailed understanding of the
underlying electron–sample interaction is essential for interpreting these signals and exploring new
regimes of electron-driven quantum dynamics.
Here, we develop a semiclassical field framework describing the coupled dynamics between a swift
electron and a quantum system represented by a time-dependent dipole response. The electron acts
as a localized electromagnetic field source, while the induced sample polarization generates a retarded
field that influences the electron evolution. This approach provides an intuitive description of energy
and momentum exchange between the electron and the material while connecting microscopic dynamics
with experimentally accessible observables. Moreover, its simplicity allows the study of spectral
alterations based on different samples, their initial states and considered electron trajectories.
The framework therefore offers a versatile platform for studying electron-driven excitation processes
and can be extended towards applications in nanoscale spectroscopy, quantum materials, and electronbased
control of light–matter interactions.