  We study the effect of transversal electric-field (E-field) on the electronic
properties of multilayer armchair-graphene-nanoribbon (AGNR). The bandgap in
multilayer-AGNRs can be reversibly modulated with the application of E-field.
At optimized widths, we obtain a semiconductor (SC) to metallic (M), as well as
M-SC transition. The AGNR electronic bands undergo vivid transformations due to
the E-field, leading to phenomena such as increase in electron velocity, change
in the sign of the electron effective mass, and the formation of linear
dispersion with massless Dirac fermions similar to 2D-graphene. These effects
are very useful and can be utilized for device applications.
