论文标题
拓扑模式的非热形变
Non-Hermitian Morphing of Topological Modes
论文作者
论文摘要
拓扑模式（TMS）通常位于更大拓扑晶格的缺陷或边界。对非热带理论的最新研究揭示了非铁皮皮肤效应（NHSE），批量作为皮肤模式崩溃到边界。在这里，我们在实验上证明了NHSE可以通过将其从边界定位到TMS的波浪函数。在关键的非热参数上，间隙TMS甚至在整个散装晶格中完全扩展，在连续体的外部形成了扩展模式。这些扩展模式仍然受散装波段拓扑的保护，使它们能够抵抗局部疾病。在一维（1D）和二维（2D）拓扑晶格以及高阶拓扑晶格中，在活跃的机械晶格中实现了定位效应。此外，通过对非热分布的明智工程，TMS可以变形为多样化的形状。我们的发现不仅扩大和加深了对TMS和NHSE的当前理解，而且还为拓扑应用开辟了新的理由。
Topological modes (TMs) are usually localized at defects or boundaries of a much larger topological lattice. Recent studies of non-Hermitian band theories unveiled the non-Hermitian skin effect (NHSE), by which the bulk states collapse to the boundary as skin modes. Here, we experimentally demonstrate that the NHSE can conversely affect wavefunctions of TMs by delocalizing them from the boundary. At a critical non-Hermitian parameter, the in-gap TMs even become completely extended in the entire bulk lattice, forming an extended mode outside of a continuum. These extended modes are still protected by bulk-band topology, making them robust against local disorders. The delocalization effect is experimentally realized in active mechanical lattices in both one-dimensional (1D) and two-dimensional (2D) topological lattices, as well as in a higher-order topological lattice. Furthermore, by the judicious engineering of the non-Hermiticity distribution, the TMs can deform into a diversity of shapes. Our findings not only broaden and deepen the current understanding of the TMs and the NHSE but also open new grounds for topological applications.
