Propagation in a periodic succession of slabs with mixed negative/positive index
Résumé
Metamaterials are artificial materials engineered using periodic inclusions of small inhomogeneities to enact effective macroscopic behavior. Until recently, most studies considered only ideal systems and did not address the possible effects of disorder.The first step in this direction was made in [Phys. Rev. B 70, 245102, 2004] where it was shown that the presence of a single defect led to the appearance of a localized mode. Since then, more general model of alternating sequences of right and left handed layers with random parameters have been studied, notably in [M. V. Gorkunov et al., Phys. Rev. E 73, 056605, 2006; Phys. Rev. Lett. 99, 193902, 2007]. The authors have shown that the localization properties differ dramatically from those exhibited by conventional disordered materials. We study wave propagation in such stratified media both experimentally and theoretically. Experiments confirm that the properties of the attenuation length differ dramatically from those exhibited by conventional alternated layer materials, notably in the intermediate value of the wavelength. Analytical prediction of the attenuation length is in good agreement with the observations.
Domaines
Acoustique [physics.class-ph]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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