物理学院 School of Physics, Nanjing University

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Zoo of Nodal-loop Metals

2018年03月16日

报告题目:Zoo of Nodal-loop Metals

报告人: 杨声远 教授
单位: Singapore University of Technology and Design
 
报告时间地点: 3月19日 星期一 下午 2:00 唐A313
 
报告简介:

Topological states of matter have been attracting great interest. Following the studies on topological insulators, the recent focus shifts towards the various topological metals (or semimetals), in which nontrivial band crossings appear near the Fermi level, endowing the low-energy electrons with novel emergent properties. In this talk, I discuss a class of metals where the band crossings form 1D loops in the Brillouin zone. I show that the loops can be characterized by several properties. Depending on how the loop winds around the Brillouin zone, it has a  characterization. The type of dispersion around the loop classifies the loop into type-I, type-II, or the hybrid type. The type-II loop shows suppressed low-frequency optical absorption, and the hybrid loop shows zero-field magnetic breakdown and distinct features in the magnetic quantum oscillations. Under spin-orbit coupling, some loops are gapped out, but some are robust owing to certain nonsymmorphic symmetries. Under proper conditions, multiple loops can exist, connect each other, and form a nodal chain.

报告人简介:
 

杨声远,江苏省南京人。2001-2002年就读于清华大学电气自动化专业。2002-2005在香港大学修读数学物理专业,获理学学士。2005-2011年在得克萨斯大学奥斯汀分校修读凝聚态物理研究生,获博士学位。2011-2013年在休斯敦CGG Veritas US Services公司工作,任地质分析成像研究员。2013年起在新加坡科技设计大学担任助理教授。以往的研究课题包括磁性材料的磁动力学,二次谐波的发射理论,反常霍尔效应,二维材料/拓扑材料的物理性质。目前的研究方向包括拓扑半金属,拓扑绝缘体,二维材料和纳米结构的物理性质,电子晶体,自旋和谷电子学,量子输运等。

 

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