Novel plasmons in topological materials--from the perspective ofsymmetry and topology

报告题目:Novel plasmons in topological materials--from the perspective ofsymmetry and topology


报告时间:2019 8 5 日 下午 3:50-4:50


报告地点:物理科技楼 101

报告摘要:The interplay between electron-electron interaction and topology of Bloch electrons in topological materials recently has attracted considerable attentions from both experimental and theoretical aspects. (1) We find that the inverted band structure with the Mexican-hat dispersion could enhance the interband correlation leading to a strong intrinsic plasmon excitation. Its frequency ranges from several meV to tens of meV and can be effectively tuned by the external fields. The electron-hole asymmetric term splits the peak of the plasmon excitation into double peaks. The fate and properties of this plasmon excitation can also act as a probe to characterize the topological phases even in lightly doped systems. We numerically demonstrate the impact of band inversion on plasmon excitations in magnetically doped thin films of three-dimensional strong topological insulators, which support the quantum anomalous Hall states (QAHE). (2) We study the chiral edge plasmons in QAH insulators and find some new and remarkable features. We offer a quantitative explanation for the recent observation of the chiral edge plasmon in QAH insulators. (3) We investigate the impacts of symmetry breaking on the plasmons in monolayer 1T’ transition metal dichalcogenides and predict a new anisotropic acoustic plasmon.

报告人简介:周建辉,中国科学院强磁场科学中心研究员,博士生导师。2012年博士研究生毕业于中国科学院物理研究所。2012-2017年先后在美国卡内基梅隆大学和香港大学从事博士后研究工作。20184月,加入中科院强磁场中心。主要从事凝聚态理论研究,包括(1)凝聚态物理中Berry相位效应;(2)拓扑材料中新奇等离激元;(3)凝聚态体系中量子反常相关的物性。在Phys. Rev. Lett., Phys. Rev. B等期刊上发表论文近20篇,引用500余次。