学术报告

报告题目: Topological Phase Transition and Transport in Nodal Line Semimetal

报告人：陈伟 南京航空航天大学教授

报告时间：2019年5月15日  上午10:00

地点：大学城校区理6-301

邀请人：周涛，王瑞强

报告摘要：

Topological nodal line semimetals (NLSs) are characterized by the crossing of the conduction and valence bands along closed loops in the Brillouin zone, which carries a π Berry flux. The topological property of the bulk states results in unique drumhead-like surface states. In this talk, I will present our recent work on new topological phase and quantum transport in NLSs. I will first show that electron-electron interaction in the NLS with two drumhead-like surface states can drive the surface states into a surface Chern insulator. Then I will discuss interesting transport results of both the surface and bulk states of the NLSs. The surface states in a spin-orbit coupled NLS exhibit spin polarization and can induce resonant spin-flipped reflection, which provides a unique evidence of the surface states. For the bulk states, we find that the torus-shaped Fermi surface and encircled π Berry flux carried by the nodal loop result in a fascinating interplay between the effective dimensionality of electron diffusion and band topology, which may lead to 3D weak localization effect or 2D weak antilocalization effect.

 

References:

[1] Wei Chen, Kun Luo, Lin Li, and Oded Zilberberg, Phys. Rev. Lett. 121, 166802 (2018).

[2] Wei Chen and J. L. Lado, Phys. Rev. Lett. 122, 016803 (2019).

[3] Wei Chen, Hai-Zhou Lu, Oded Zilberberg, arXiv:1902.06921 (PRL accepted)

 

报告人简介:

陈伟，现为南京航空航天大学教授，2014年南京大学博士毕业，获博士学位，后加入南京航空航天大学物理系工作，2016年评为副教授，2018年破格晋升为教授。2017到2019年在瑞士苏黎世联邦理工学院理论物理研究所做访问学者。

    陈伟教授主要从事凝聚态物理的理论研究，研究方向包括介观系统和拓扑材料的量子输运以及在量子信息方面的潜在应用，低功耗器件以及自旋电子学，在相关领域发表论文20多篇，包括5篇第一作者的PRL论文，以及1篇高被引的PRB论文。