Control of multimodal topological edge modes in magnetoelastic lattices

One-dimensional topological acoustic systems offer robust signal transmission and localization in compact spaces. Here, we demonstrate the ability to control both longitudinal and transverse topological waves in a quasi-one-dimensional elastic lattice, composed of an array of repelling magnets connected to elastic cantilevers. The two different topological modes can be separately or simultaneously excited at selected frequencies. Our system enables controlled multimodal propagation and edge localization, owing to its finite size and to the design of longitudinal and transverse topological band gaps within similar frequency ranges. In addition to the robustness of the topological modes to unintentional disorder, we show that disorder can couple degrees of freedom and tailor the energy distribution between longitudinal and transverse waves. This system may enable other studies on the interactions of topological modes useful in sensing and information-processing applications.