2019/02/28 by Konstantin Y. Bliokh, Franco Nori · 1 citation
Physics and Astronomy · #Acoustic wave #Geometry #Hermitian matrix #Operator (biology) #Photon #Physics #Quantum Mechanics and Non-Hermitian Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Surface (topology) #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #physics.class-ph #physics.optics #quant-ph
paper · pdf · doi:10.1103/physrevlett.123.054301
published as Phys. Rev. Lett. 123, 054301 (2019) · 6 pages, 2 figures, and Supplemental Material. To appear in Phys. Rev. Lett
arxiv created 2019/07/11 · openalex publication_date 2019/08/01 · arxiv updated 2019/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recently, it was shown that surface electromagnetic waves at interfaces between continuous homogeneous media (e.g., surface plasmon-polaritons at metal-dielectric interfaces) have a topological origin [K. Y. Bliokh et al., Nat. Commun. 10, 580 (2019)NCAOBW2041-172310.1038/s41467-019-08397-6]. This is explained by the nontrivial topology of the non-Hermitian photon helicity operator in the Weyl-like representation of Maxwell equations. Here we analyze another type of classical waves: longitudinal acoustic waves corresponding to spinless phonons. We show that surface acoustic waves, which appear at interfaces between media with opposite-sign densities, can be explained by similar topological features and the bulk-boundary correspondence. However, in contrast to photons, the topological properties of sound waves originate from the non-Hermitian four-momentum operator in the Klein-Gordon representation of acoustic fields.