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

作　　者：Qing-Ya Cheng Yue-E Xie Xiao-Hong Yan Yuan-Ping Chen 程青亚;谢月娥;颜晓红;陈元平(School of Physics and Electronic Engineering,Jiangsu University,Zhenjiang 212013,China;School of Physics and Optoelectronics,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]School of Physics and Electronic Engineering,Jiangsu University,Zhenjiang 212013,China [2]School of Physics and Optoelectronics,Xiangtan University,Xiangtan 411105,China

出　　处：《Chinese Physics B》2022年第11期460-464,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12174157,12074150,and 11874314)。

摘　　要：An ideal type-Ⅲnodal point is generated by crossing a completely flat band and a dispersive band along a certain momentum direction.To date,the type-Ⅲnodal 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-Ⅲnodal 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-ⅢDirac points.In two of the structures,consisting of triangular carbon rings,the type-ⅢDirac 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-ⅢDirac points,but also provides 2D materials for exploring their physical properties experimentally.

关 键 词：diamond-like lattice carbon materials type-ⅢDirac points 

分 类 号：O469[理学—凝聚态物理]