二维谷声子晶体拓扑绝缘体的高阶拓扑角态  

Higher-Order Topological Corner States in 2D Valley Phononic Crystals Topological Insulators

作　　者：蒋婧 孔鹏 邓科[1] JIANG Jing;KONG Peng;DENG Ke(School of Physics and Electromechanical Engineering,Jishou University,Jishou 416000,Hunan China)

机构地区：[1]吉首大学物理与机电工程学院,湖南吉首416000

出　　处：《吉首大学学报(自然科学版)》2025年第1期39-44,共6页Journal of Jishou University(Natural Sciences Edition)

摘　　要：基于量子谷霍尔效应,设计了一种具有C_(3v)对称的二维谷声子晶体拓扑绝缘体,通过旋转晶格内部散射体的角度改变晶格的拓扑特性,并利用不同拓扑相的二维谷声子晶体构造超胞结构,进而对高阶拓扑角态进行探究.结果表明,旋转角度时,体系的对称性会从C_(3v)对称降为C_(3)对称;当-30°<θ<0°时,体系对应非平庸相,而当0°<θ<30°,体系则对应平庸相;当内部晶格具有非平庸相、外部晶格具有平庸相时,超胞结构Zigzag边界的角落处有3个连续角态,而当内部晶格具有平庸相、外部晶格具有非平庸相时,超胞结构中不存在角态;引入无序缺陷的前后,角态的本征场分布无明显变化,显示出良好的鲁棒性.Based on the quantum valley-hall effect,a two-dimensional valley phononic crystal topological insulator with C_(3v) symmetry has been designed.By rotating the angle of the scatterers inside the lattice,the topological properties of the lattice were changed.A supercell structure was constructed using two-dimensional valley phononic crystals with different topological phases,and the high-order topological corner states were investigated.The results show that when the rotation angle is changed,the symmetry of the system will decrease from C_(3v) symmetry to C_(3) symmetry.When-30°<θ<0°,the system corresponds to a non-trivial phase,while when 0°<θ<30°,the system corresponds to a trivial phase.When the internal lattice has a non-trivial phase and the external lattice has a trivial phase,there are three continuous corner states at the corners of the Zigzag boundary of the supercell structure.However,when the internal lattice has a trivial phase and the external lattice has a non-trivial phase,there are no corner states in the supercell structure.Before and after introducing disorder defects,the intrinsic field distribution of the corner states shows no significant change,demonstrating good robustness.

关 键 词：拓扑绝缘体 声子晶体 量子谷霍尔效应 角态 

分 类 号：O424[理学—声学]