中国物理B ›› 2016, Vol. 25 ›› Issue (11): 117106-117106.doi: 10.1088/1674-1056/25/11/117106

所属专题: TOPICAL REVIEW — Topological electronic states

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Topological nodal line semimetals

Chen Fang(方辰), Hongming Weng(翁红明), Xi Dai(戴希), Zhong Fang(方忠)   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing, China
  • 收稿日期:2016-09-11 修回日期:2016-10-24 出版日期:2016-11-05 发布日期:2016-11-05
  • 通讯作者: Chen Fang, Hongming Weng E-mail:cfang@iphy.ac.cn;hmweng@iphy.ac.cn
  • 基金资助:

    Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFA0302400 and 2016YFA0300604), partially by the National Natural Science Foundation of China (Grant Nos. 11274359 and 11422428), the National Basic Research Program of China (Grant No. 2013CB921700), and the "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant No. XDB07020100).

Topological nodal line semimetals

Chen Fang(方辰)1, Hongming Weng(翁红明)1,2, Xi Dai(戴希)1,2, Zhong Fang(方忠)1,2   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing, China
  • Received:2016-09-11 Revised:2016-10-24 Online:2016-11-05 Published:2016-11-05
  • Contact: Chen Fang, Hongming Weng E-mail:cfang@iphy.ac.cn;hmweng@iphy.ac.cn
  • Supported by:

    Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFA0302400 and 2016YFA0300604), partially by the National Natural Science Foundation of China (Grant Nos. 11274359 and 11422428), the National Basic Research Program of China (Grant No. 2013CB921700), and the "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant No. XDB07020100).

摘要:

We review the recent, mainly theoretical, progress in the study of topological nodal line semimetals in three dimensions. In these semimetals, the conduction and the valence bands cross each other along a one-dimensional curve in the three-dimensional Brillouin zone, and any perturbation that preserves a certain symmetry group (generated by either spatial symmetries or time-reversal symmetry) cannot remove this crossing line and open a full direct gap between the two bands. The nodal line(s) is hence topologically protected by the symmetry group, and can be associated with a topological invariant. In this review, (i) we enumerate the symmetry groups that may protect a topological nodal line; (ii) we write down the explicit form of the topological invariant for each of these symmetry groups in terms of the wave functions on the Fermi surface, establishing a topological classification; (iii) for certain classes, we review the proposals for the realization of these semimetals in real materials; (iv) we discuss different scenarios that when the protecting symmetry is broken, how a topological nodal line semimetal becomes Weyl semimetals, Dirac semimetals, and other topological phases; and (v) we discuss the possible physical effects accessible to experimental probes in these materials.

关键词: topological semimetals, nodal band structures, topological invariatns

Abstract:

We review the recent, mainly theoretical, progress in the study of topological nodal line semimetals in three dimensions. In these semimetals, the conduction and the valence bands cross each other along a one-dimensional curve in the three-dimensional Brillouin zone, and any perturbation that preserves a certain symmetry group (generated by either spatial symmetries or time-reversal symmetry) cannot remove this crossing line and open a full direct gap between the two bands. The nodal line(s) is hence topologically protected by the symmetry group, and can be associated with a topological invariant. In this review, (i) we enumerate the symmetry groups that may protect a topological nodal line; (ii) we write down the explicit form of the topological invariant for each of these symmetry groups in terms of the wave functions on the Fermi surface, establishing a topological classification; (iii) for certain classes, we review the proposals for the realization of these semimetals in real materials; (iv) we discuss different scenarios that when the protecting symmetry is broken, how a topological nodal line semimetal becomes Weyl semimetals, Dirac semimetals, and other topological phases; and (v) we discuss the possible physical effects accessible to experimental probes in these materials.

Key words: topological semimetals, nodal band structures, topological invariatns

中图分类号:  (Electron density of states and band structure of crystalline solids)

  • 71.20.-b
73.20.-r (Electron states at surfaces and interfaces)