The electronic spectrum of three coupled graphene layers (graphene trilayers) is investigated in the presence of an external magnetic field. We obtain analytical expressions for the Landau level spectrum for both the $ABA$ and $ABC$ type of stacking, which exhibit very different dependence on the magnetic field. We show that layer asymmetry and an external gate voltage can strongly influence the properties of the system.

• Received 1 July 2011

DOI:https://doi.org/10.1103/PhysRevB.84.205448