2017年11月29日(周三)15:00-15:40,旗山校区理工楼3#303,张海军教授,学术讲座【Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T’-WTe2】

发布时间: 2017-11-27 访问次数: 351

学术讲座【Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T’-WTe2】

来源:lol比赛投注网站 时间:2017年11月29日(周三)15:00-15:40




张海军,2004年获中国科学技术大学理学学士学位,2009年获中国科学院物理研究所博士学位,2010-2015年于美国Stanford大学从事博士后研究,2015年被南京大学聘为教授。2011年荣获香港求是基金会“求是杰出科技成就集体奖”,奖励在设计和发现三维拓扑绝缘体方面的贡献。2015年入选中组部‘千人计划’青年项目。2016年入选江苏省“双创计划”。张海军教授长期活跃在拓扑量子态领域的学术前沿,在量子自旋霍尔效应、量子反常霍尔效应、三维拓扑绝缘体、强相互作用拓扑绝缘体、拓扑超导体和拓扑半金属等多种拓扑量子态预测和物性研究方面取得了一系列具有国际影响力的原创性成果。目前发表学术论文40余篇,包括国际权威学术杂志Science,Nature Physics、Nature Materials,Nature Nanotechnology、Nature Communications、PRL、PRB等。论文总引用>12,000次。


The two-dimensional topological insulators (2DTI) host a full gap in the bulk band, induced by spin-orbit coupling (SOC) effect, together with the topologically protected gapless edge states. However, the SOC-induced gap is usually small, and it is challenging to suppress the bulk conductance and thus to realize the quantum spin Hall (QSH) effect. In this study, we find a novel mechanism to effectively suppress the bulk conductance. By using the quasiparticle interference (QPI) technique with scanning tunneling spectroscopy (STS), we demonstrate that the QSH candidate single-layer 1T’-WTe2 has a semimetal bulk band structure with no full SOC-induced gap. Surprisingly, in this two-dimensional system, we find the electron interactions open a Coulomb gap which is always pinned at the Fermi energy (EF). The opening of the Coulomb gap can efficiently diminish the bulk state at the EF and is in favor of the observation of the quantized conduction of topological edge states.