当前位置: X-MOL 学术Phys. Rev. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Observation of Non-Abelian Nodal Links in Photonics.
Physical Review Letters ( IF 8.6 ) Pub Date : 2020-07-14 , DOI: 10.1103/physrevlett.125.033901
Erchan Yang 1, 2 , Biao Yang 3 , Oubo You 1, 2 , Hsun-Chi Chan 1, 2 , Peng Mao 2 , Qinghua Guo 4 , Shaojie Ma 1, 2 , Lingbo Xia 2 , Dianyuan Fan 1 , Yuanjiang Xiang 5 , Shuang Zhang 2
Affiliation  

In crystals, two bands may cross each other and form degeneracies along a closed loop in the three-dimensional momentum space, which is called nodal line. Nodal line degeneracy can be designed to exhibit various configurations such as nodal rings, chains, links, and knots. Very recently, non-Abelian band topology was proposed in nodal link systems, where the nodal lines formed by consecutive pairs of bands exhibit interesting braiding structures and the underlying topological charges are described by quaternions. Here, we experimentally demonstrate non-Abelian nodal links in a biaxial hyperbolic metamaterial. The linked nodal lines threading through each other are formed by the crossings between three adjacent bands. Based on the non-Abelian charges, we further analyze various admissible nodal link configurations for the three-band system. On the interface between the metamaterial and air, surface bound states in the continuum are observed, which serves as the symmetry-enforced derivative of drumhead surface states from the linked nodal lines. Our work serves as a direct observation of the global topological structures of nodal links, and provides a platform for studying non-Abelian topological charge in the momentum space.

中文翻译:

光子学中非阿贝尔节点链接的观察。

在晶体中,两个能带可能会彼此交叉并沿着三维动量空间中的闭环(称为节点线)形成简并性。可以将节点线的简并性设计为具有各种配置,例如节点环,链,链节和结。最近,在节点链接系统中提出了非阿贝尔频带拓扑,其中由连续对频带形成的节点线表现出有趣的编织结构,而底层的拓扑电荷由四元数描述。在这里,我们通过实验证明了双轴双曲线超材料中的非阿贝尔节点链接。彼此穿过的链接的节线是由三个相邻带之间的交叉形成的。基于非阿贝尔电荷,我们进一步分析了三频带系统的各种允许的节点链路配置。在超材料与空气之间的界面上,观察到连续体中的表面束缚状态,它充当鼓面表面状态从链接节点线的对称增强导数。我们的工作直接观察了节点链接的全球拓扑结构,并为研究动量空间中的非阿贝尔拓扑电荷提供了一个平台。
更新日期:2020-07-14
down
wechat
bug