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arXiv · 2602.07417

Continuum model for the terahertz dielectric response of glasses

Tatsuya Mori·Hideyuki Mizuno·Yuzuki Motokawa·Dan Kyotani·Soo Han Oh·Yasuhiro Fujii·Akitoshi Koreeda·Shinji Kohara·Seiji Kojima
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Abstract

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 it highlights the dominant role of transverse shear dynamics.

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Tatsuya Mori, Hideyuki Mizuno, Yuzuki Motokawa, Dan Kyotani, Soo Han Oh, Yasuhiro Fujii, Akitoshi Koreeda, Shinji Kohara, Seiji Kojima. 2026-02-07. Continuum model for the terahertz dielectric response of glasses. https://doi.org/10.1103/sjkh-zd6t

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