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第二类拓扑金属

已有 476 次阅读 2020-5-16 12:56 |系统分类:科研笔记


TOPICAL REVIEW 

Front. Phys. 15(4), 43201 (2020), arXiv: 2003.03328 (12 pages) 
链接:http://journal.hep.com.cn/fop/en/10.1007/s11467-020-0963-7

 

 

拓扑金属是一种特殊的金属材料,它在费米能附近具有非平庸的能带交叉,并产生特殊的准粒子激发。拓扑金属可以根据这些能带交叉的特征进行分类。例如,根据能带交叉点的维度,拓扑金属可以分为节点、节线和节面金属。拓扑金属另一个重要的特性是色散的类型。根据交叉点附近能带色散的倾斜程度,我们可以有第一类和第二类色散。由于第一类和第二类拓扑金属具有截然不同的费米面拓扑,这会导致材料的物理性质具有显著差异。本文简要回顾了这一研究方向的最新进展,重点介绍了第二类节点和节线拓扑金属的概念、物理特性和材料实现。

 

Type-II topological metals

Si Li¹,², Zhi-Ming Yu³,Yugui Yao³, Shengyuan A. Yang²
¹Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, China
²Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
³Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, Beijing 100081, China


Topological metals (TMs) are a kind of special metallic materials, which feature nontrivial band crossings near the Fermi energy, giving rise to peculiar quasiparticle excitations. TMs can be classified based on the characteristics of these band crossings. For example, according to the dimensionality of the crossing, TMs can be classified into nodal-point, nodal-line, and nodal-surface metals. Another important property is the type of dispersion. According to degree of the tilt of the local dispersion around the crossing, we have type-I and type-II dispersions. This leads to significant distinctions in the physical properties of the materials, owing to their contrasting Fermi surface topologies. In this article, we briefly review the recent advances in this research direction, focusing on the concepts, the physical properties, and the material realizations of the type-II nodal-point and nodal-line TMs.

Keywords type-II, nodal point, nodal line, topological metals

             Contents
1. Introduction 

2. Type-II nodal point

    2.1 Concept

    2.2 Physical property

    2.3 Material realization

3. Type-II nodal line
   3.1 Concept
   3.2 Physical property
   3.3 Material realization 

4. Hybrid nodal line

5. Summary and outlook

Acknowledgements
References