论文标题
连续，对称的双狄拉克锥和拓扑上的非平凡声子（c $ _ {4v} $和c $ _ {2v} $）单元单元单元格
Double Dirac Cones and Topologically Non-Trivial Phonons for Continuous, Square Symmetric (C$_{4v}$ and C$_{2v}$) Unit Cells
论文作者
论文摘要
由于语音拓扑绝缘子主要是在离散研究中研究的，因此具有C $ _ {6} $或C $ _ {3} $六边形对称性的石墨烯状结构，因此一个开放的问题是如何使用连续的，非甲状腺突出的单个单元组系统地实现双脏圆锥和拓扑上的非拓扑锥和拓扑上的非拓扑结构。在这里，我们通过提出一种新颖的计算方法来解决这一挑战，用于连续二维正方形音调超材料的逆设计，展示了C $ _ {4V} $和C $ _ {2V} $对称性。这导致了方形单元拓扑的系统设计，表现出双重狄拉克变性，从而实现了基于量子旋转厅效应（QSHE）的拓扑保护的界面传播。数值模拟证明，螺旋边缘状态在两个拓扑不同的正方形语音超材料之间的界面中出现，这打开了基于QSHE基于QSHE的假蛋白依赖性传输的可能性。
Because phononic topological insulators have primarily been studied in discrete, graphene-like structures with C$_{6}$ or C$_{3}$ hexagonal symmetry, an open question is how to systematically achieve double Dirac cones and topologically non-trivial structures using continuous, non-hexagonal unit cells. Here, we address this challenge by presenting a novel computational methodology for the inverse design of continuous two-dimensional square phononic metamaterials exhibiting C$_{4v}$ and C$_{2v}$ symmetry. This leads to the systematic design of square unit cell topologies exhibiting a double Dirac degeneracy, which enables topologically-protected interface propagation based on the quantum spin Hall effect (QSHE). Numerical simulations prove that helical edge states emerge at the interface between two topologically distinct square phononic metamaterials, which opens the possibility of QSHE-based pseudospin-dependent transport beyond hexagonal lattices.
