中国物理B ›› 2022, Vol. 31 ›› Issue (11): 117101-117101.doi: 10.1088/1674-1056/ac7c00

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Robust and intrinsic type-III nodal points in a diamond-like lattice

Qing-Ya Cheng(程青亚)1,2, Yue-E Xie(谢月娥)1,2,†, Xiao-Hong Yan(颜晓红)2, and Yuan-Ping Chen(陈元平)1,2,‡   

  1. 1 School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang 212013, China;
    2 School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China
  • 收稿日期:2022-05-11 修回日期:2022-06-19 接受日期:2022-06-27 出版日期:2022-10-17 发布日期:2022-11-01
  • 通讯作者: Yue-E Xie, Yuan-Ping Chen E-mail:Yueex@ujs.edu.cn;Chenyp@ujs.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12174157, 12074150, and 11874314).

Robust and intrinsic type-III nodal points in a diamond-like lattice

Qing-Ya Cheng(程青亚)1,2, Yue-E Xie(谢月娥)1,2,†, Xiao-Hong Yan(颜晓红)2, and Yuan-Ping Chen(陈元平)1,2,‡   

  1. 1 School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang 212013, China;
    2 School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China
  • Received:2022-05-11 Revised:2022-06-19 Accepted:2022-06-27 Online:2022-10-17 Published:2022-11-01
  • Contact: Yue-E Xie, Yuan-Ping Chen E-mail:Yueex@ujs.edu.cn;Chenyp@ujs.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12174157, 12074150, and 11874314).

摘要: An ideal type-III nodal point is generated by crossing a completely flat band and a dispersive band along a certain momentum direction. To date, the type-III nodal points found in two-dimensional (2D) materials have been mostly accidental and random rather than ideal cases, and no one mentions what kind of lattice can produce ideal nodal points. Here, we propose that ideal type-III nodal points can be obtained in a diamond-like lattice. The flat bands in the lattice originate from destructive interference of wavefunctions, and thus are intrinsic and robust. Moreover, the specific lattice can be realized in some 2D carbon networks, such as T-graphene and its derivatives. All the carbon structures possess type-III Dirac points. In two of the structures, consisting of triangular carbon rings, the type-III Dirac points are located just on the Fermi level and the Fermi surface is very clean. Our research not only opens a door to finding the ideal type-III Dirac points, but also provides 2D materials for exploring their physical properties experimentally.

关键词: diamond-like lattice, carbon materials, type-III Dirac points

Abstract: An ideal type-III nodal point is generated by crossing a completely flat band and a dispersive band along a certain momentum direction. To date, the type-III nodal points found in two-dimensional (2D) materials have been mostly accidental and random rather than ideal cases, and no one mentions what kind of lattice can produce ideal nodal points. Here, we propose that ideal type-III nodal points can be obtained in a diamond-like lattice. The flat bands in the lattice originate from destructive interference of wavefunctions, and thus are intrinsic and robust. Moreover, the specific lattice can be realized in some 2D carbon networks, such as T-graphene and its derivatives. All the carbon structures possess type-III Dirac points. In two of the structures, consisting of triangular carbon rings, the type-III Dirac points are located just on the Fermi level and the Fermi surface is very clean. Our research not only opens a door to finding the ideal type-III Dirac points, but also provides 2D materials for exploring their physical properties experimentally.

Key words: diamond-like lattice, carbon materials, type-III Dirac points

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

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73.22.-f (Electronic structure of nanoscale materials and related systems)