We introduce the acoustic equivalent of 'supercoupling' by studying the anomalous sound transmission and uniform energy squeezing through ultranarrow acoustic channels filled with zero-density metamaterials. We propose their realization by inserting transverse membranes with a subwavelength period along the channel, and we prove a novel form of acoustic tunneling based on impedance matching and infinite phase velocity at the zero-density operation. We envision applications in sensing, noise control, cloaking and energy harvesting.
@article{arxiv.1210.8056,
title = {Extraordinary Sound Transmission through Density-Near-Zero Ultranarrow Channels},
author = {Romain Fleury and Andrea Alu},
journal= {arXiv preprint arXiv:1210.8056},
year = {2015}
}