论文标题
非线性三链链超晶格的带变性和进化
Band degeneration and evolution in nonlinear triatomic chain superlattices
论文作者
论文摘要
非线性超级晶格具有独特的功能，可进行波浪操作。尽管受到了越来越多的关注，但强烈非线性超级晶格中带结构和带隙的基本物理机制以及带镜的演变过程仍不清楚。在这里，我们建立并检查了强烈的非线性超级晶格模型（三个三局模型），以根据分析和数值方法来显示典型的非线性条带结构的进化过程。我们发现，强烈的非线性超晶格呈现特定的带变性和分叉，并伴有其单位细胞中的振动模式转移。考虑到模式转移，阐明了不同模型中带变性的演化过程和物理机制。观察到的变性可能会发生，因为分散曲线的转移，分叉，缩短，合并或消失，这取决于耦合的非线性元件的排列。同时，晶胞的尺寸降低了带盖的频率范围和机制（布拉格和局部共振）的变化。这些发现回答了对非线性周期性结构，非线性晶体和非线性超材料的研究的一些创始问题，这些问题是广泛物理社区所感兴趣的
Nonlinear superlattices exhibit unique features allowing for wave manipulations. Despite the increasing attention received, the underlying physical mechanisms and the evolution process of the band structures and bandgaps in strongly nonlinear superlattices remain unclear. Here we establish and examine strongly nonlinear superlattice models (three triatomic models) to show the evolution process of typical nonlinear band structures based on analytical and numerical approaches. We find that the strongly nonlinear superlattices present particular band degeneration and bifurcation, accompanied with the vibration mode transfer in their unit cells. The evolution processes and the physical mechanisms of the band degeneration in different models are clarified with the consideration of the mode transfer. The observed degeneration may occur as the shifting, bifurcating, shortening, merging or disappearing of dispersion curves, all depending on the arrangement of the coupled nonlinear elements. Meanwhile, the dimension of the unit cell reduces, alongside changes in the frequency range and mechanisms (Bragg and local resonance) of the bandgaps. These findings answer some foundamental questions peritinent to the study of nonlinear periodic structures, nonlinear crystals and nonlinear metamaterials, which are of interest to the broad community of physics
