Ultrasonic wave transport in concentrated disordered resonant emulsions
Abstract
We show how resonant (near-field) coupling affects wave transport in disordered media through ultrasonic experiments in concentrated suspensions. The samples consist of resonant emulsions in which oil droplets are suspended in a liquid gel. By varying the volume fraction of droplets φ up to 40%, the limits of the independent scattering approximation are experimentally demonstrated as soon as φ > 10%. For these concentrated samples, the proximity of resonant scatterers induces a renormalization of the surrounding medium, leading to a reduction in scattering strength. Hence, maximum scattering is reached at an intermediate droplet concentration (20% < φ < 30%) where subdiffusive wave transport is observed. These results are very relevant for designing materials for the study of wave transport phenomena such as Anderson localization.
Domains
Acoustics [physics.class-ph]Origin | Publisher files allowed on an open archive |
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