Time- and frequency-domain study for electron beams penetrating dielectric nanospheres: fingerprints of Cherenkov and transition radiation
Abstract
We present a theoretical study of Cherenkov and transition radiation for swift electron beams penetrating dielectric nanospheres using material models of different sophistication. Specifically, we perform a combined time-domain (numerically, via the discontinuous Galerkin time-domain method) and frequency-domain (numerically and analytically, via Mie-based theory) study, including the induced-field distribution, cathodoluminescence (CL) multipole/directional decomposition, as well as the time-dependent angular power flow. For low velocities below the Cherenkov threshold, we show that transition radiation is dominant in the far-field CL, and the near-fields at the transition points are primarily responsible for the main features observed in the far-field. For higher velocities far beyond the Cherenkov threshold, we identify the fingerprints of the observable Cherenkov front. Specifically, a constant-permittivity model allows us to isolate the respective contributions of CR and TR to the far-field radiation, thereby facilitating the interpretation of the results for a more realistic material model that includes material resonances. Our combined time- and frequency-domain framework provides a direct view of radiative excitation channels for swift electron beams penetrating dielectric nanoparticles, thereby revealing their interplay beyond the conventional frequency-domain analyses.
Versions
Related
- Optical fingerprints across the strain-driven semi-Dirac transition in Kekulé-O graphene
- The Casimir free energy of peptide films on a silicon substrate: Impact of dielectric-to-metal transition in silicon and nanoparticles in peptide
- Finite-Frequency Boson-Number Bounds Across the Quantum Rabi Transition
- Absolute frequency measurement of the 40Ca+ clock transition using a GNSS link to the SI second
- Nuclear Charge Radii of Sr Isotopes: Reevaluation based on Transition Frequency Measurements in the 5s−5p−4d manifold in Sr+
BibTeX
@misc{zhao2026time,
title = {{Time- and frequency-domain study for electron beams penetrating dielectric nanospheres: fingerprints of Cherenkov and transition radiation}},
author = {Wenhua Zhao and Christos Tserkezis and N. Asger Mortensen and Kurt Busch},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2606.20081},
eprint = {2606.20081},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.20081},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Time- and frequency-domain study for electron beams penetrating dielectric nanospheres: fingerprints of Cherenkov and transition radiation
AU - Wenhua Zhao
AU - Christos Tserkezis
AU - N. Asger Mortensen
AU - Kurt Busch
PY - 2026
DA - 2026/08/17
PB - arXiv
DO - 10.48550/arxiv.2606.20081
UR - https://arxiv.org/abs/2606.20081
AB - We present a theoretical study of Cherenkov and transition radiation for swift electron beams penetrating dielectric nanospheres using material models of different sophistication. Specifically, we perform a combined time-domain (numerically, via the discontinuous Galerkin time-domain method) and frequency-domain (numerically and analytically, via Mie-based theory) study, including the induced-field distribution, cathodoluminescence (CL) multipole/directional decomposition, as well as the time-dependent angular power flow. For low velocities below the Cherenkov threshold, we show that transition radiation is dominant in the far-field CL, and the near-fields at the transition points are primarily responsible for the main features observed in the far-field. For higher velocities far beyond the Cherenkov threshold, we identify the fingerprints of the observable Cherenkov front. Specifically, a constant-permittivity model allows us to isolate the respective contributions of CR and TR to the far-field radiation, thereby facilitating the interpretation of the results for a more realistic material model that includes material resonances. Our combined time- and frequency-domain framework provides a direct view of radiative excitation channels for swift electron beams penetrating dielectric nanoparticles, thereby revealing their interplay beyond the conventional frequency-domain analyses.
ER -