Boson peak dynamics in glasses produce a robust crossover in the terahertz (THz) dielectric response that standard Debye or Lorentz models do not capture. We develop a continuum description of this THz response, coupling an infrared-effective charge fluctuation spectrum to a frequency-dependent shear modulus, and apply it to glycerol glass. The model reproduces the measured complex dielectric function and the nearly linear infrared light-vibration coupling around the boson peak, and highlights the dominant role of transverse shear dynamics.
@article{arxiv.2602.07417,
title = {Continuum model for the terahertz dielectric response of glasses},
author = {Tatsuya Mori and Hideyuki Mizuno and Yuzuki Motokawa and Dan Kyotani and Soo Han Oh and Yasuhiro Fujii and Akitoshi Koreeda and Shinji Kohara and Seiji Kojima},
journal= {arXiv preprint arXiv:2602.07417},
year = {2026}
}
Comments
4 figures in the main text and 4 figures in the Supplemental Material (included)