Impurity effects on electrical conductivity of doped bilayer graphene in the presence of a bias voltage
Lotfi E1, †, , Rezania H2, Arghavaninia B3, Yarmohammadi M4
       

The honeycomb structure. The light dashed lines denote the Bravais lattice unit cell. Each cell includes two nonequivalent sites, which are indicated by A and B. a1 and a2 are the primitive vectors of the unit cell. a01, a02, and a03 are three vectors that connect the nearest neighbor sites.