On the design of non-Hermitian elastic metamaterial for broadband perfect absorbers

Elastic metamaterial, an engineered artificial material, has received much attention in physics and engineering communities due to its functional properties unavailable natural materials. However, most elastic metamaterials, especially for their two-dimensional structures, belong the Hermitian category, making them difficult adapt real lossy structures explore loss modulation. In present study, non-Hermitian loss-modulation beam plate models based on complex wavenumber plane, structural dynamics, mode-coupling scattering theory are established design metamaterials (LEMs) any solid material. Based a unified closed-form solution absorption, subwavelength lightweight LEM can cope with conventional challenge of achieving broadband near-omnidirectional wave perfect absorption. We reveal here high-performance absorption from greatly enhanced wave-energy dissipation by combination dissipation-radiation-balance multiple reflections system. numerically experimentally verify effectiveness theoretical model demonstrate plate-like structure. Our work not only opens new route achieve low-frequency vibration suppression macro devices microelectromechanical systems, more essentially, but it also provides effective paradigm systems.