Lattice thermal transport from phonon spectra beyond perturbation theory
Materials Science
2026-04-22 v1
Abstract
We develop a molecular dynamics framework to compute the mode-resolved phonon spectral density from classical correlations of an annihilation-like phonon variable. For harmonic oscillators, classical molecular dynamics exactly reproduces the corresponding quantum Kubo-transformed correlator, providing the basis for extension to anharmonic systems. Using PbTe as a benchmark and CsBiICl as a strongly anharmonic test case, we show that the method captures both quasiparticle and non-Lorentzian spectra beyond perturbative quasiparticle theory, while yielding thermal conductivity in good agreement with experiment. This framework provides a direct route from classical molecular dynamics to quantum-mechanical Wigner heat transport in solids.
Keywords
Cite
@article{arxiv.2604.19615,
title = {Lattice thermal transport from phonon spectra beyond perturbation theory},
author = {Zezhu Zeng and Michele Simoncelli and David E. Manolopoulos},
journal= {arXiv preprint arXiv:2604.19615},
year = {2026}
}