标题： 声学超材料中反螺旋边缘态的观察 显示英文标题

标题： Observation of Anti-helical Edge States in Acoustic Metamaterials

摘要： 作为量子霍尔效应的标志性特征，手性边缘模式（CEMs）沿条带结构的两个平行边缘反向传播。 然而，最近的研究表明存在反直觉的反CEMs，它们沿平行边缘同向传播。 类似于在量子自旋霍尔效应中已建立的手性边缘模式（CEMs）扩展为螺旋边缘模式（HEMs），自然地将反CEMs扩展为反HEMs，反HEMs由一对时间反演相关的反CEMs组成。 在本信中，我们报告了基于具有交错正负层间跃迁的双层模型的反HEMs的首次观察。 实验上，我们在声学平台上实现了这种反螺旋模型，并通过选择性激发不同的自旋子空间，以及识别体能谱中的能量偏置狄拉克点，提供了反HEMs的有力证据。 我们的发现可能为物质的拓扑相提供新的见解，并可能为设计具有独特边缘输运特性的新型器件铺平道路。 显示英文摘要

摘要： As a hallmark of the quantum Hall effect, chiral edge modes (CEMs) counterpropagate along the two parallel edges of a ribbon structure. However, recent studies demonstrate counterintuitive antiCEMs that copropagate along the parallel edges. Analogous to the established extension of the CEMs to helical edge modes (HEMs) in the quantum spin Hall effect, it is natural to extend the antiCEMs to antiHEMs, which comprise a pair of time-reversal-related antiCEMs. In this Letter, we report the first observation of the antiHEMs based on a bilayer model that features staggered positive and negative interlayer hoppings. Experimentally, we implement this anti-helical model on an acoustic platform and provide compelling evidence for the antiHEMs by selectively exciting different spin subspaces, along with identifying the energybiased Dirac points in bulk spectra. Our findings may offer new insights into topological phases of matter and potentially pave the way for designing novel devices with unique edge transport properties.