Vector vibrations and the Ioffe-Regel crossover in disordered lattices
Disordered Systems and Neural Networks
2009-11-07 v1 Materials Science
Abstract
The spectral density for vector vibrations in the f.c.c. lattice with force-constant disorder is analysed within the coherent potential approximation. The phase diagram showing the weak- and strong-scattering regimes is presented and compared with that for electrons. The weak-scattering regime for external long-wavelength vibrational plane waves is shown to be due to sum-rule correlations in the dynamical matrix. A secondary peak below the Brillouin peak for sufficiently large wavevectors is found for the lattice models. The results obtained are supported by precise numerical solutions.
Cite
@article{arxiv.cond-mat/0204549,
title = {Vector vibrations and the Ioffe-Regel crossover in disordered lattices},
author = {S. N. Taraskin and S. R. Elliott},
journal= {arXiv preprint arXiv:cond-mat/0204549},
year = {2009}
}
Comments
21 pages, 13 figures