Non-reciprocal and Topological Wave Phenomena in Acoustics

For nearly two decades, the field of acoustic metamaterials (AMM) has investigated the potential for acoustic and elastic wave control through the design of sub-wavelength material structure. This Special Issue contains contributions focused on the emerging challenge in AMM to model, design, and experimentally verify the behavior of non-reciprocal acoustical media, i.e., materials that allow one to hear but not be heard. Contributions fall into one of two categories: i) periodic media that display non-reciprocal or symmetry-protected topological acoustic modes inspired by quantum mechanical analogues and ii) non-reciprocal acoustical media that break one or more assumptions of linear, time-invariance.

Guest Editors: Romain Fleury, Michael R. Haberman, Guoliang Huang, and Andrew N. Norris