当前位置:首页  教学科研

学术讲座【Magnetic topological semimetals】

时间:2017-11-28浏览:60设置

时间:2017年11月29日(周三)15:40-16:20

地点:旗山校区理工3号楼303会议室

主讲:华中科技大学国家脉冲强磁场中心 徐刚教授

主办:物理与能源学院、福建省量子调控与新能源材料重点实验室、福建省太阳能转换与储能工程技术研究中心

专家简介:徐刚,2010年获中国科学院物理研究所博士学位,2010-2012年任中科院物理所助理研究员,2012-2016在美国斯坦福大学做访问研究,现在华中科技大学国家脉冲强磁场中心工作,入选第十三批千人计划“青年项目”。主要从事新奇物性和材料的第一性原理计算和理论研究,研究兴趣包括:铁基超导、拓扑物质态,新型二维功能材料。已发表学术论文36篇,总引用4000多次,H因子21;其中Nature子刊、PRL等国际顶级期刊16篇,另有2篇论文入选“2008年中国百篇最具影响国际学术论文”。重要成果:1)成功预言了铁基超导母体材料中的条纹状反铁磁基态—铁基超导获得国家自然科学一等奖的代表性工作之一;2)把凝聚态中电子态按照拓扑分类的概念从绝缘体推广到了半金属,首先提出双外尔半金属的概念,开启了Weyl费米子的研究热潮,引用达600多次。

报告摘要:In a 3D solid, the low energy excitation of the non-degenerate linearly dispersive band crossing exactly satisfies the Weyl equation. Such band crossing is named Weyl node (WN), and such solid is known as the Weyl semimetal (WSM), which should exhibit remarkable features, such as magnetic monopoles, Fermi arcs and Weyl anomaly. Here I report that fruitful topological phases can be realized in a specific honeycomb lattice, including the ideal WSM, unstable double-Weyl semimetal, 3D strong topological insulator, nodal line semimetal, and a novel semimetal consisting of both WNs and nodal-lines. Guiding by this model, we demonstrate that GdSI is the long-pursuing ideal WSM with two pairs of WNs residing at the Fermi level. Furthermore, I'd like to introduce the other stable double-Weyl semimetal, HgCr2Se, which has a single pair of double-Weyl fermions separated in momentum space. Quantum anomalous Hall Effect can be achieved in its quantum-well structure.


返回原图
/