High Magnetic Field Laboratory, Chinese Academy of Sciences

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. 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). We also study the chiral edge plasmons in QAHE and find new and remarkable features of chiral edge plasmons. We offer a quantitative explanation for the recent observation of the chiral edge plasmon in QAHE. One work thus sheds some new light on the potential applications of topological materials in plasmonics.

Reference: Furu Zhang, Jianhui Zhou, Di Xiao and Yugui Yao, Phys. Rev. Lett. 119, 266804 (2017); A. C. Mahoney et al, Nat. Commun 8, 1836 (2017); Furu Zhang, Jianhui Zhou, Di Xiao and Yugui Yao, In preparation (2019). 

报告人简介：

周建辉，中国科学院强磁场科学中心研究员。2012年毕业于中国科学院物理研究所，并于2013年获博士学位。2012年到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，2018年4月加入中科院强磁场科学中心任研究员。长期从事固体中Berry相位效应的研究，目前主要关注综合极端条件下（强磁场、超高压、极低温）拓扑材料中的新奇物性（输运、光学、多体物理）、拓扑材料中的等离激元、凝聚态体系中量子反常相关的物理效应。迄今在Phys Rev Lett、Phys Rev B等国际期刊发表论文十余篇，拓扑半金属中输运理论的工作于2017年获得第二届中国科协优秀科技论文奖。

邀请人：  朱学涛  副研究员（电话：82649008）

联系人：  刘   淼  副研究员（电话：82649407）