Ultra-slow sound in non-resonant meta-aerogel

• DOI: 10.48550/arxiv.2003.09059
• Publication Date: 2020-01-01
• Authors: Ai Du; Yuhan Xie; Yan Li; Yongdong Pan; WU Guang-ming; Bin Zhou
• Keywords: Condensed Matter - Materials Science; 0103 physical sciences; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Physics - Applied Physics; Applied Physics (physics.app-ph); 01 natural sciences

The manipulation of sound with acoustic metamaterials is a field intense research, where interaction via resonance common application despite the significant disadvantages. We propose novel procedure for introducing well-designed coupling interfaces cell size less than 10 nm into an ultra-soft porous medium, to prepare meta-aerogel, propagation significantly delayed in non-resonant mode. resultant velocity shown as scaling law mass density and fraction ratio components, accordance our analytical model. have prepared meta-aerogel slowest 62 m/s. To best knowledge, this lowest value compact solid materials, prospect further slowing down by procedure. development such meta-aerogels can facilitate key applications intended employ type slow (or phase delay). Examples latter include deep subwavelength meta-surface other focused imaging or transformation acoustics that require high contrast velocity.