Figure 1
From: Helical edge states and edge-state transport in strained armchair graphene nanoribbons
The honeycomb lattice geometry. The lattice structure of graphene is made out of two interpenetrating triangular lattices (a 1 and a 2 are the lattice unit vectors). The nearest-neighbor vectors are \(\mathop{{\delta }_{1}}\limits^{\longrightarrow}\), \(\mathop{{\delta }_{2}}\limits^{\longrightarrow}\), and \(\mathop{{\delta }_{3}}\limits^{\longrightarrow}\). The armchair edge is at the x direction, and Strain is along the y direction.
