Tunneling phenomenon in non-Hermitian classic systems

Our research explores non-Hermitian elastic lattices with non-local feedback interactions. Proportional feedback in one-dimensional lattices creates complex dispersion relations that exhibit non-reciprocity with gain and loss in opposite directions. This behavior persists across multiple frequency bands. In classical systems, we observed peculiar tunneling phenomena in one-dimensional chains with non-reciprocity. Our findings highlight the fundamental properties of non-Hermitian elastic lattices and suggest opportunities for designing meta materials with unique functionalities such as wave filtering, amplification, and localization.