Following the realization of Weyl semimetals in quantum electronic materials, classical wave analogues of Weyl materials have also been theorized and experimentally demonstrated in photonics and acoustics. Weyl points in elastic systems, however, have been a much more recent discovery. In this study, we report on the design of an elastic fully-continuum three-dimensional material that, while offering structural and load-bearing functionalities, is also capable of Weyl degeneracies and surface topologically-protected modes in a way completely analogous to the quantum mechanical counterpart. The topological characteristics of the lattice are obtained by \textit{ab initio} numerical calculations without employing any further simplifications. The results clearly characterize the topological structure of the Weyl points and are in full agreement with the expectations of surface topological modes. Finally, full field numerical simulations are used to confirm the existence of surface states and to illustrate their extreme robustness towards lattice disorder and defects.

中文翻译：

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三维夹心型弹性晶格中的外尔点和拓扑表面态

随着外尔半金属在量子电子材料中的实现，外尔材料的经典波类似物也在光子学和声学中被理论化和实验证明。然而，弹性系统中的外尔点是最近的发现。在这项研究中，我们报告了一种弹性全连续三维材料的设计，该材料在提供结构和承载功能的同时，还能够以完全类似于量子力学的方式进行外尔简并和表面拓扑保护模式。机械对应。晶格的拓扑特征是通过 \textit{ab initio} 数值计算获得的，没有采用任何进一步的简化。结果清楚地表征了外尔点的拓扑结构，并且与表面拓扑模式的预期完全一致。最后，使用全场数值模拟来确认表面状态的存在，并说明它们对晶格无序和缺陷的极端鲁棒性。