Data from: Ultra-low and ultra-broad-band nonlinear acoustic metamaterials

Linear acoustic metamaterials (LAMs)are widely used to manipulate sound, but it is challenging to obtain bandgaps withthe generalized width (the ratio of the bandgap width to its start frequency) γ>1 based on linear mechanisms.Here, we adopt both theoretical and experimental approaches todescribe the nonlinear chaotic mechanism in both one-dimensional (1D) and two-dimensional (2D)nonlinear acoustic metamaterials (NAMs). This mechanismenables the strongly NAMsto reduce the transmission of wave by as much as 20-40dB in an ultra-low and ultra-broad bandthat consists of bandgaps and chaotic bands.With the subwavelength cells, the generalized width reachesγ=21 in a 1D NAM and it goes up to γ=39 in a 2D NAM, which overcomesthe limit of bandwidth for wave suppression in current LAMs.Our work allows for further progress in the understanding of the dynamics of NAMs and it opens up avenuesindouble-ultra acoustic manipulations.线性声学超材料（linear acoustic metamaterials, LAMs）被广泛应用于声波调控领域，但基于线性机制，难以获得广义带宽（带隙宽度与带隙起始频率的比值）γ>1的声学带隙。本文结合理论与实验手段，对一维（1D）和二维（2D）非线性声学超材料（nonlinear acoustic metamaterials, NAMs）中的非线性混沌机制进行了系统阐述。该机制可使此类非线性声学超材料在由带隙与混沌带构成的超低频超宽带频段内，将声波透射率最高抑制20~40 dB。借助亚波长单元，一维非线性声学超材料的广义带宽可达γ=21，二维非线性声学超材料的广义带宽更是提升至γ=39，突破了当前线性声学超材料的声波抑制带宽瓶颈。本研究不仅深化了对非线性声学超材料动力学特性的认知，更为超低频超宽带声波调控开辟了全新研究路径。