Metamaterial gap in amplitude for elastic vector solitons

Tinuku - Following John Scott Russell’s observation of nonlinear water wave packets propagating with stable shape and constant velocity in the Union Canal in Scotland, the unique properties of solitons have been studied and exploited in many areas of science and engineering.

Focusing on mechanical systems, granular crystals have been found to provide an effective platform for the propagation of highly nonlinear solitary waves and have enabled the design of impact mitigation layers, lenses, switches, and non-destructive detection techniques.

Tinuku Metamaterial gap in amplitude for elastic vector solitons

However, the solitons observed in granular media are of scalar nature and lack the multiple polarizations typical of elastic waves propagating in solid materials. A tema of the Harvard University in Cambridge and Le Mans Université combine experimental, numerical, and analytical tools to design highly nonlinear mechanical metamaterials that exhibit a new phenomenon.

Gaps in amplitude for elastic vector solitons. Such gaps are fundamentally different from the spectral gaps in frequency typically observed in linear phononic crystals and acoustic metamaterials and are induced by the lack of strong coupling between the two polarizations of the vector soliton.

“We show that the amplitude gaps are a robust feature of our system and that their width can be controlled both by varying the structural properties of the units and by breaking the symmetry in the underlying geometry,” said Bolei Deng of the Harvard University and colleagues,

“Moreover, we demonstrate that amplitude gaps provide new opportunities to manipulate highly nonlinear elastic pulses, as demonstrated by the designed soliton splitters and diodes,” said Deng, report to Nature Communications