  Double layer graphene is a gapless semiconductor which develops a finite gap
when the layers are placed at different electrostatic potentials. We study,
within the tight-biding approximation, the electronic properties of the gaped
graphene bilayer in the presence of disorder, perpendicular magnetic field, and
transverse electric field. We show that the gap is rather stable in the
presence of diagonal disorder. We compute the cyclotron effective mass in the
semi-classical approximation, valid at low magnetic fields. Landau level
formation is clearly seen in zigzag and armchair ribbons of the gaped bilayer
at intermediate magnetic fields.
