2020/06/10 by Habib Ammari, Ammari, Habib, Erik Orvehed Hiltunen +1
Engineering · Physics and Astronomy · #35C20 #35J05 #35P20 #Analysis of PDEs (math.AP) #FOS: Mathematics #Geophysics and Sensor Technology #Quantum Mechanics and Non-Hermitian Physics #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.48550/arxiv.2006.05719
openalex publication_date 2020/06/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Wave scattering structures with amplification and dissipation can be modelled by non-Hermitian systems, opening new ways to control waves at small length scales. In this work, we study the phenomenon of topologically protected edge states in acoustic systems with gain and loss. We demonstrate that localized edge modes appear in a periodic structure of subwavelength resonators with a defect in the gain/loss distribution, and explicitly compute the corresponding frequency and decay length. Similarly to the Hermitian case, these edge modes can be attributed to the winding of the eigenmodes. In the non-Hermitian case, the topological invariants fail to be quantized, but can nevertheless predict the existence of localized edge modes.