Phononic crystals: Harnessing the propagation of sound, elastic waves, and phonons (foreword)
Résumé
Phononic crystals are artificial periodic structures that can alter efficiently the flow of sound in air, of acoustic waves in fluids, or of elastic waves in solids. They were introduced about twenty years ago [1,2] and have gained increasing interest since then, both because of their amazing physical properties and because of their potential applications. The topic of phononic crystals [3–5] stands at the cross-road of several fields of physics – condensed matter physics, wave propagation in inhomogeneous and periodic media – and engineering – acoustics, ultrasonics, mechanical engineering, and electrical engineering. Phononic crystals cover a wide range of scales, from meter-size periodic structures for sound in air to nanometer-size structures for information processing or thermal phonon control in integrated circuits. They furthermore offer a practical implementation for the paradigms of acoustic metamaterials. The articles in this dossier illustrate several of these aspects.