Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · cond-mat/9808024

Universal correlations in vibrational spectra of complex crystals

G. Fagas·Vladimir I. Fal'ko·C. J. Lambert
View original source ↗Read source document ↗Export metadata ↓

Abstract

We study spectral statistics of lattice modes in a disordered crystal and in a crystal with a complex unit cell. The correlations of the eigenmode frequencies of a block of a disordered solid is found to obey the GOE Wigner-Dyson statistics. In contrast, the set of eigenfrequencies of a crystal with a complex unit cell taken at the same point ${\bf Q}\not=0$ in the Brillouin zone exhibit correlations specific to the GUE universality class.

Explore related subjects

cond-mat

Keep this discovery

BibTeXRIS

G. Fagas, Vladimir I. Fal'ko, C. J. Lambert. 1998-08-03. Universal correlations in vibrational spectra of complex crystals. https://doi.org/10.1016/s0921-4526(98)01208-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2015

Spectral Representation for the Effective Macroscopic Response of a Polycrystal: Application to Third-Order Nonlinear Susceptibility

Erratum: In our paper, we show that the spectral representation for isotropic two-component composites also applies to uniaxial polycrystals. We have learned that this result was, in fact, first conjectured by G.W. Milton. While our derivation is more detailed, our result for the spectral function is the same as Milton's. We very much regret not having been aware of this work at the time of writing our paper. Original abstract: We extend the spectral theory used for the calculation of the effective linear response functions of composites to the case of a polycrystalline material with uniaxially anisotropic microscopic symmetry. As an application, we combine these results with a nonlinear decoupling approximation as modified by Ma et al., to calculate the third-order nonlinear optical susceptibility of a uniaxial polycrystal, assuming that the effective dielectric function of the polycrystal can be calculated within the effective-medium approximation.

cond-mat↗
arXiv2014

Towards quantum well hot hole lasers

It should be possible to improve hot-hole laser performance by moving from bulk materials to a quantum well structure. The extra design parameters enable us to alter the band structure by changing the crystal orientation of the growth direction; to use the well width to shift the subband offsets, enabling the effect of the LO phonon scattering cut-off to be controlled; and to use modulation doping to ensure a high hole concentration to increase the gain without the dopants being present in the gain region. We present the first simulations of THz quantum well hot-hole lasers that can produce inversion and optical gain.

cond-mat↗