Fast topological pumping of vibrational energy in non-Hermitian mechanical systems and its application as elastic beam splitter

By modulating key parameters in mechanical systems, topological pumping enables energy transfer in the form of elastic vibrations between the boundaries of a structure. The essential factor of topological pumping is the adiabaticity, which restricts the rate of parameter variation and consequently limits the speed of energy transfer. In this work, we report a non-Hermitian strategy for ultrafast corner-to-corner and edge-to-edge energy transfer in time-varying 2D and 3D elastic lattices by active control in the form of gain and loss. With the help of relevant fidelity indicators, the critical adiabatic modulation times are precisely determined, demonstrating an improvement of tens to hundreds of times in the energy transfer speed for non-Hermitian systems compared to their Hermitian counterparts. Validated through a novel split-flow device, the proposed design strategy enables fast and robust splitting of elastic vibrational energy, opening an avenue for energy manipulation.