物理学报2024，Vol.73Issue(15)：63-69,7.DOI:10.7498/aps.73.20240640
声学四极子拓扑绝缘体中的位错态
Dislocation defect states in acoustic quadrupole topological insulators
摘要
Abstract
Quadrupole topological insulator(QTI)is the first proposed higher-order topological phase of matter with quantized quadrupole moment but zero dipole moment.The QTI has expanded widely the traditional bulk-boundary correspondence,thereby the lower-dimensional topological boundary state can be observed.The recent interest has turned to the bulk-dislocation correspondence,which dominates the topological states localized to disclinations,and links the reciprocal-space topology of lattices with the appearance of dislocation states.Recently,many research groups have turned the studies of dislocation defects to classical wave systems.In these researches,the method of inducing dislocation defects is to remove a portion of the lattices of topological insulator and then rearrange the remaining lattices of the topological insulator.Through such a method,the micro structure of the lattices is changed,but it is difficult to realize in the actual operation.In this work,we study the dislocation defect states in acoustic QTIs.The acoustic QTI is designed by reversing the magnitude of the intracellular and extracellular coupling in the system,and the bulk energy bands and topological corner states are studied.Subsequently,by introducing partial trivial lattices into acoustic QTI structure,the dislocation bound states are generated in the corner formed by two different topological phases,which can be characterized by a 1/2 quantized fractional charge.The robustness of the topological dislocation states is verified by introducing the imperfection inside the system.Further,it is demonstrated that the dislocation positions can be designed at will.Without changing the microstructure of the lattice,we successfully modulate the line dislocation states and bulk dislocation states.The topological dislocation states studied in this work broaden the types of higher-order topological states in artificial structures,and provide new insights into the acoustic applications of higher-order topological insulators,such as sensing and high-performance energy harvesting.关键词
四极子拓扑绝缘体/声子晶体/位错态Key words
quadrupole topological insulator/phononic crystal/dislocation defect states引用本文复制引用
蒋婧,王小云,孔鹏,赵鹤平,何兆剑,邓科..声学四极子拓扑绝缘体中的位错态[J].物理学报,2024,73(15):63-69,7.基金项目
国家自然科学基金(批准号:11964011)资助的课题.Project supported by the National Natural Science Foundation of China(Grant No.11964011). （批准号:11964011）
