Deng Weiyin, Lu Jiuyang, Li Feng, Huang Xueqin, Yan Mou, Ma Jiahong, Liu Zhengyou
School of Physics and Optoelectronics, South China University of Technology, 510640, Guangzhou, Guangdong, China.
Key Laboratory of Artificial Micro- and Nanostructures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China.
Nat Commun. 2019 Apr 16;10(1):1769. doi: 10.1038/s41467-019-09820-8.
Three-dimensional topological nodal lines, the touching curves of two bands in momentum space, which give rise to drumhead surface states, provide an opportunity to explore a variety of exotic phenomena. However, solid evidence for a flat drumhead surface state remains elusive. In this paper, we report a realization of three-dimensional nodal line dispersions and drumhead surface states in phononic crystal. Profiting from its macroscopic nature, the phononic crystal permits a flexible and accurate fabrication for materials with ring-like nodal lines and drumhead surface states. Phononic nodal rings of the lowest two bands and, more importantly, topological drumhead surface states are unambiguously demonstrated. Our system provides an ideal platform to explore the intriguing properties of acoustic waves endowed with extraordinary dispersions.
三维拓扑节线是动量空间中两个能带的接触曲线，会产生鼓面表面态，为探索各种奇异现象提供了契机。然而，关于平坦鼓面表面态的确凿证据仍然难以获得。在本文中，我们报告了在声子晶体中实现三维节线色散和鼓面表面态的情况。得益于其宏观特性，声子晶体允许对具有环状节线和鼓面表面态的材料进行灵活且精确的制造。明确展示了最低两个能带的声子节环，更重要的是，展示了拓扑鼓面表面态。我们的系统为探索具有非凡色散的声波的有趣特性提供了一个理想平台。
