基于Su-Schrieffer-Heeger模型的声学界面态和边缘态
Su-Schrieffer-Heeger Model Inspired Acoustic Interface States and Edge States
摘要：
当我们在保持周期系统对称性的情况下连续变形时，如果一个完整的带隙关闭然后重新打开，通常会发生拓扑相变。在凝聚态物理中，一个证明这种拓扑相变的常见模型是Su-Schrieffer-Heeger（SSH）模型。众所周知，两个不同的拓扑阶段出现时，小区内的跳变从小到大，相对于小区间跳变的模型。前一种情况是拓扑平凡的，而后一种情况是拓扑非平凡的。在这里，我们设计了一个1D周期性的声学系统，完全类似于SSH模型。声学系统的单元由两个谐振器和两个连接它们的连接管组成。我们表明，拓扑相变发生在我们的声学模拟，当我们调整的半径的连接管，控制胞间和胞内跳跃。拓扑相变的特征是几何Zak相的突变。实验测量了该声学模拟物的非平凡相和平凡相之间的拓扑界面态，结果与数值结果吻合得很好。此外，我们表明，拓扑非平凡的阶段，我们的声学模拟的SSH模型可以支持边缘状态，在此讨论是缺乏在以前的作品拓扑声学。边缘状态对局部缺陷和扰动是鲁棒的。
英文摘要：
If a full band gap closes and then reopens when we continuously deform a periodic system while keeping its symmetry, a topological phase transition usually occurs. A common model demonstrating such a topological phase transition in condensed matter physics is the Su-Schrieffer-Heeger (SSH) model. As well known, two distinct topological phases emerge when the intracell hopping is tuned from smaller to larger with respect to the intercell hopping in the model. The former case is topologically trivial, while the latter case is topologically non-trivial. Here, we design a 1D periodic acoustic system in exact analogy to the SSH model. The unit cell of the acoustic system is composed of two resonators and two junction tubes connecting them. We show that the topological phase transition happens in our acoustic analog when we tune the radii of the junction tubes which control the intercell and intracell hoppings. The topological phase transition is characterized by the abrupt change of the geometric Zak phase. The topological interface states between non-trivial and trivial phases of our acoustic analog are experimentally measured, and the results agree very well with the numerical values. Further, we show that topologically non-trivial phases of our acoustic analog of the SSH model can support edge states, on which the discussion is absent in previous works about topological acoustics. The edge states are robust against localized defects and perturbations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
