Azugraphene: a new graphene-like hexagonal carbon allotrope with Dirac cones

Abstract

Azugraphene is a new graphene-like hexagonal carbon allotrope with Dirac cones and is potentially synthesizable from its fragments: azulene.

Dirac Semimetal Protected by Nonsymmorphic Mirror Symmetries in TPH‐Graphene

“…Besides hexagonal systems, the Dirac points can exist in 2D orthorhombic and tetragonal systems, including α-graphdiyne, [40] S-graphene, [41] palgraphyne, [10] and HOT graphene. [42] Further, azugraphene, [43] StoneÀWales graphene, [44] borophosphene, [45] cp-graphyne, [19] and circumcoro-graphyne [46] also exhibit linear band dispersion and associated Dirac points. However, most of the synthesized 2D carbon materials are protected by hexagonal symmetry.…”

Auxetic ographene: a new 2D Dirac nodal-ring semimetal carbon-based material with a high negative Poisson's ratio

“…Graphdiyne 5 as a typical 2D carbon material exhibits outstanding properties and applications, such as gas separation, 6,7 catalysis, 8,9 and energy-related fields. 10 Motivated by the widespread applications and fascinating properties of graphdiyne, numerous two-dimensional carbon-based materials with metallic [11][12][13] or semimetal [14][15][16][17][18] and semiconductor 19,20 properties have been predicted using theoretical calculations. However, most 2D carbon allotropes exhibit metallic or semiconductor characteristics and few materials possess Dirac cone structures let alone Dirac nodal ring structures.…”

Grain Boundaries Induced a Class of Carbon Allotropes with Dirac Fermions

“…13,14 Among them, it is divided into zero-dimensional NPS 15 of the type-I NPS and the type-II NPS, and one-dimensional nodal line semimetal 16,17 according to the position of the Dirac point and the shape of the topological band. 18,19 There are twisted type-I Dirac cones of Azugraphene, 20 SW-graphene, 21 and PHH-graphene, 22 which is attributed to the fact that part of the hexagonal ring in the complete graphene is replaced by the pentagonal and heptagonal carbon rings. The dispersion near the type-II Dirac cone of OPG-Z 23 and SW40 24 has a large tilt, so that the point type Fermi surface (type-I Dirac cones) is transformed into a coexisted electron and hole pockets Fermi surface.…”