Extraordinary Sound Transmission through Density-Near-Zero Ultranarrow Channels

摘要

We introduce the acoustic equivalent of 'supercoupling' by studying theanomalous sound transmission and uniform energy squeezing through ultranarrowacoustic channels filled with zero-density metamaterials. We propose theirrealization by inserting transverse membranes with a subwavelength period alongthe channel, and we prove a novel form of acoustic tunneling based on impedancematching and infinite phase velocity at the zero-density operation. We envisionapplications in sensing, noise control, cloaking and energy harvesting.