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一点彩票刘动身副传授讲座告诉
公布人:王燚  公布工夫:2019-08-25   阅读次数:10

应一点彩票网李伟奇副传授约请,北方科技大学刘奇航研讨员将于827日对一点彩票网举行接见,接见时代将举行学术讲述并举行交换,迎接列位感兴味的师生加入。

问题:磁性拓扑绝缘体的失常量子霍尔效应

工夫827日上午10:00

地址:理学楼308

择要As one of paradigmatic phenomena in condensed matter physics, the quantum anomalous Hall effect (QAHE) in stoichiometricChern insulators has drawn great interest for years. Recently, MnBi2Te4 thin films manifests the QAH effect at a record high temperature of 4.5 K in the forced ferromagnetic state above 10 Tesla. By realizing a bulk MnBi4Te7 with alternating [MnBi2Te4]and [Bi2Te3] layers, we suggest that it is a Z2 antiferromagnetic topological insulator with a small out-of-plane saturation field of ~ 0.2 Tesla. Using model Hamiltonian analysis and first-principle calculations, we then establish a topological phase diagram and map on it with different two-dimensional configurations, which is taken from the recently-grown magnetic topological insulators MnBi4Te7 and MnBi6Te10. These configurations manifest various topological phases, including quantum spin Hall effect with and without time-reversal symmetry, as well as QAHE. We then provide design principles to trigger QAHE by tuning experimentally accessible knobs, such as slab thickness and magnetization. Our work reveals that superlattice-like magnetic topological insulators with tunable exchange interaction serve as an ideal platform to realize the long-sought QAHE in pristine compounds.

讲述人简介:刘奇航,北方科技大学物理系副传授,中组部2018年“国度特聘青年专家”当选者,次要从事以密度泛函实际为主的凝结态实际研讨,聚焦真实质料。研讨兴味包罗明白质料中新颖的电学,磁学,光学,缺陷,自旋极化,拓扑等性子及它们的耦合,以及功效导向的新型质料设计及展望。刘奇航博士以第一作者或通讯作者身份已揭晓包罗Nature. PhysicsNature. CommunicationsPhysical.Review. XPhysical. Review. LettersNano LettersAdvanced. Functional. Materials.等多篇学术论文;署名作者合计已揭晓学术论文40余篇,Google Scholar统计援用跨越2900次;担当Physical. Review. LettersNano LettersAdvanced. Materials等期刊审稿人。