Nanoscale Phononic Crystals and Structures

Abstract

The objective of this chapter is to explore advances in the development of phononic crystals and phononic structures at the nanoscale. The downscaling of phononic structures to nanometric dimensions requires an atomic treatment of the constitutive materials. At the nanoscale, the propagation of phonons may not be completely ballistic (wave-like) and nonlinear phenomena such as phonon–phonon scattering occur. We apply second-order perturbation theory to a one-dimensional anharmonic crystal to shed light on phonon self-interaction and three-phonon scattering processes. We emphasize the competition between dispersion effects induced by the structure, anharmonicity of the atomic bonds, and boundary scattering. These phenomena are illustrated by several examples of atomistic models of nanoscale phononic structures simulated using the method of molecular dynamics (MD). Special attention is also paid to size effects.