Work

Lattice dynamics of disordered phases of silicon and spatially resolved computations of thermal conductivity

Year: 2026

Type: preprint

Abstract: The lattice dynamics of disordered systems (amorphous solids, polymers and glasses) are often distinct from crystalline analogues. Examples include the "two-level systems" and the Boson peak. Here, we show that even the venerable material amorphous silicon offers new wrinkles: (1) realistic networks studied with DFT-quality interatomic potentials show the existence of harmonic modes exhibiting anomalously large root-mean-square variation in atomic positions, and (2) these dynamics determine the processes of heat transport. We correlate the atomic dynamics with transport using the site-projected thermal conductivity [C. Ugwumadu et. al Phys. Status Solidi B 263, e202500316 (2026)], and conjecture that these observations are relevant to other disordered systems.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2610.10165

Authors: Gautam, A., Ugwumadu, C., Rosset, L. A. M., Tutchton, R. M., Nakhmanson, S., Drabold, D. A.

Institutions: Ohio University, Los Alamos National Laboratory, University of Oxford, University of Connecticut

Language: English

Topic: Thermal properties of materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Energy, National Nuclear Security Administration, Office of Naval Research, Laboratory Directed Research and Development, Los Alamos National Laboratory

Awards: G1017065088, G1279347439, G2356915424, G2821339390, MRI: Track 1 Acquisition of a university-wide computational cluster, G5913129343, G6086272066, G6410514744, G6563880843, G70659677

OpenAlex ID: W7220996882

Cites: 19

Cited by: 1

Related to: 10