拓扑节线半金属研究进展

Research progress on topological nodal line semimetals

拓扑量子材料包括拓扑绝缘体、拓扑半金属和拓扑超导体等,是现代凝聚态物理和材料科学的研究重点.本文旨在简要介绍近年来关于拓扑节线半金属材料的研究结果,并重点阐述本课题组在这一领域的最新研究进展.拓扑节线半金属主要可通过能带的简并和色散两个方面来进行分类.在能带的简并方面本文主要介绍不同对称性保护的节线半金属:在时间反演对称性存在的体系中由点式空间群和非点式空间群保护的节线半金属;在时间反演破缺体系中磁序和拓扑序耦合的节线半金属.在能带的色散关系方面,本文主要介绍具有高次色散的高阶节线半金属和由能带倾斜效应导致的第二类节线半金属.

Topological quantum materials,such as topological insulators,topological semimetals,and topological superconductors,are the research focus of modern condensed matter physics and materials science.The purpose of this article is to give a brief introduction on the research progress of topological nodal line semimetal materials in recent years,and to focus on the latest research progress of our group in this field.Topological semimetals can be classified mainly by two aspects:energy band degeneracy and dispersion.In terms of energy band degeneracy,this article will introduce nodal line semimetals protected by different symmetries including nodal line semimetals protected by symmorphic space groups and non-symmorphic space groups in the system with time reversion symmetry,and nodal line semimetals coupled with magnetic and topological orders without time reversion symmetry,respectively.In terms of energy band dispersion,this article will introduce high-order nodal line semimetals and type-II nodal line semimetals.