报告题目：Magnetic topological semimetals

报告人：徐刚 教授（华中科技大学国家脉冲强磁场中心）

报告时间：10月20日(星期五)下午3点

报告地点：物理学院新楼五楼多功能报告厅

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.

报告人简介：徐刚教授， 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。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，新型二维功能材料等，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，另有两篇论文入选“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550多次。

邀请人：余睿教授