论文标题
在三维声学拓扑绝缘子中观察狄拉克层次结构
Observation of Dirac hierarchy in three-dimensional acoustic topological insulators
论文作者
论文摘要
狄拉克锥（DCS）在各种独特现象中起关键作用，从石墨烯中的无质量电子到拓扑绝缘体（TIS）中的稳健表面状态。从理论上讲，最近的研究揭示了一个完整的狄拉克层次结构，其中包括八倍的散装直流，四倍的表面DC和双重铰链DC，与拓扑阶段的层次结构相关，包括使用相同的3D基础Lattice，包括三阶三维（3D）拓扑仪，包括三阶三维（3D）拓扑器。在这里，我们报告了3D声学中狄拉克层次结构的第一个实验性观察。使用声学测量值，我们明确地揭示了每个层次结构中的多率DC提升可以诱导二维（2D）拓扑表面状态，在一阶3D Ti，一维拓扑状态的一阶（1d）拓扑状态的一阶三阶DC中，在第二阶三阶式零件和Zere Zero intodications（Zero）的第三阶dc中，三级（1d）拓扑中的dc中有四倍（Zero）的第三级（0）（均为3D）。 ti。我们的工作不仅扩大了狄拉克物理学的基本研究范围，而且还为多维强大的波浪操作打开了新的途径。
Dirac cones (DCs) play a pivotal role in various unique phenomena ranging from massless electrons in graphene to robust surface states in topological insulators (TIs). Recent studies have theoretically revealed a full Dirac hierarchy comprising an eightfold bulk DC, a fourfold surface DC, and a twofold hinge DC, associated with a hierarchy of topological phases including first-order to third-order three-dimensional (3D) topological insulators, using the same 3D base lattice. Here, we report the first experimental observation of the Dirac hierarchy in 3D acoustic TIs. Using acoustic measurements, we unambiguously reveal that lifting of multifold DCs in each hierarchy can induce two-dimensional (2D) topological surface states with a fourfold DC in a first-order 3D TI, one-dimensional (1D) topological hinge states with a twofold DC in a second-order 3D TI, and zero-dimensional (0D) topological corner states in a third-order 3D TI. Our work not only expands the fundamental research scope of Dirac physics, but also opens up a new route for multidimensional robust wave manipulation.
