Fig. 4. (a) Band structure of the graphene. The valence and conduction bands touch at discrete points in the Brillouin zone. Reproduced with permission of Physics Today, 59(1), 21 (2006). (b) Schematic illustration (i) of bandgap opening in bilayer graphene by an electric field. (ii) Schematic of the device used to open the gap. (iii) Transfer characteristics of the graphene FET. Reproduced with permission of IEDM Tech. Digest, 23.1.1, 552 (2010)

Fig. 4. (a) Band structure of the graphene. The valence and conduction
bands touch at discrete points in the Brillouin zone. Reproduced with
permission of Physics Today, 59(1), 21 (2006). (b) Schematic illustration
(i) of bandgap opening in bilayer graphene by an electric field. (ii) Schematic
of the device used to open the gap. (iii) Transfer characteristics of the
graphene FET. Reproduced with permission of IEDM Tech. Digest, 23.1.1,
552 (2010)