2018/11/30 by Konstantin Y. Bliokh, Franco Nori · 1 voice · 4 citations
Computer Science · Engineering · Materials Science · Physics and Astronomy · #Acoustic Wave Phenomena Research #Metamaterials and Metasurfaces Applications #Speech and Audio Processing #physics.class-ph #physics.optics
paper · pdf · doi:10.1103/physrevb.99.020301
published as Phys. Rev. B 99, 020301 (2019) · 10 pages, 2 figures, 1 table, to appear in Phys. Rev. B
arxiv created 2018/12/18 · openalex publication_date 2019/01/03 · arxiv updated 2019/01/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We consider spin angular momentum density in inhomogeneous acoustic fields: evanescent waves and surface waves at interfaces with negative-density metamaterials. Despite being purely longitudinal (curl-free), acoustic waves possess intrinsic vector properties described by the velocity field. Motivated by the recent description and observation of the spin properties in elastic and acoustic waves, we compare these properties with their well-known electromagnetic counterparts. Surprisingly, both the transverse spin of evanescent waves and the parameters of surface waves are very similar in electromagnetism and acoustics. We also briefly analyze the important role of dispersion in the description of the energy and spin densities in acoustic metamaterials.