Details

Autor(en) / Beteiligte

• Zhang, L. Z
• Wang, Z. F
• Wang, Zhiming M
• Du, S. X
• Gao, H.-J
• Liu, Feng

Titel

Highly Anisotropic Dirac Fermions in Square Graphynes

Ist Teil von

• The journal of physical chemistry letters, 2015-08, Vol.6 (15), p.2959-2962

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We predict a family of 2D carbon (C) allotropes, square graphynes (S-graphynes) that exhibit highly anisotropic Dirac fermions, using first-principle calculations within density functional theory. They have a square unit-cell containing two sizes of square C rings. The equal-energy contour of their 3D band structure shows a crescent shape, and the Dirac crescent has varying Fermi velocities from 0.6 × 105 to 7.2 × 105 m/s along different k directions. Near the Fermi level, the Dirac crescent can be nicely expressed by an extended 2D Dirac model Hamiltonian. Furthermore, tight-binding band fitting reveals that the Dirac crescent originates from the next-nearest-neighbor interactions between C atoms. S-graphynes may be used to build new 2D electronic devices taking advantages of their highly directional charge transport.