Dynamics and topology of non-Hermitian elastic lattices with non-local feedback control interactions
Dynamics and topology of non-Hermitian elastic lattices with non-local feedback control interactions
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DOI：
10.1088/1367-2630/ab81b6
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发表时间：
2020-05-01
影响因子：
3.3
通讯作者：
Ruzzene, Massimo
中科院分区：
文献类型：
--
作者：
Rosa, Matheus I. N.;Ruzzene, Massimo
我们研究非厄米弹性晶格的非局部反馈相互作用的特点。在一维晶格中，比例反馈产生与复杂色散关系相关的非互易性，其特征在于在相反的传播方向上的增益和损耗。对于非局部控制，这种非互易性发生在以相反的非互易行为为特征的多个频带上。色散拓扑结构的研究重点是绕组数和非厄米趋肤效应，这体现了通过本地化的有限晶格的边界处的体模。在二维晶格中，非互易性与定向波放大有关。此外，在两个方向上的集肤效应的组合产生的模式是本地化的有限二维晶格的角落。我们的研究结果描述了非厄米弹性晶格的基本性质，并提出了新的可能性设计的Meta材料与选择性滤波，放大和本地化的新功能。所考虑的非局部晶格也提供了一个平台，为调查的拓扑相位的非厄米特系统。
We investigate non-Hermitian elastic lattices characterized by non-local feedback interactions. In one-dimensional lattices, proportional feedback produces non-reciprocity associated with complex dispersion relations characterized by gain and loss in opposite propagation directions. For non-local controls, such non-reciprocity occurs over multiple frequency bands characterized by opposite non-reciprocal behavior. The dispersion topology is investigated with focus on winding numbers and non-Hermitian skin effect, which manifests itself through bulk modes localized at the boundaries of finite lattices. In two-dimensional lattices, non-reciprocity is associated with directional wave amplification. Moreover, the combination of skin effect in two directions produces modes that are localized at the corners of finite two-dimensional lattices. Our results describe fundamental properties of non-Hermitian elastic lattices, and suggest new possibilities for the design of meta materials with novel functionalities related to selective wave filtering, amplification and localization. The considered non-local lattices also provide a platform for the investigation of topological phases of non-Hermitian systems.