We demonstrate that the electronic spectrum of graphene in a one-dimensional periodic potential will develop a Landau level spectrum when the potential magnitude varies slowly in space. The effect is related to extra Dirac points generated by the potential whose positions are sensitive to its magnitude. We exploit a chiral symmetry in the Dirac Hamiltonian description with a superlattice potential to show that the low energy theory contains an effective magnetic field. Numerical diagonalization of the Dirac equation confirms the presence of Landau levels. Possible consequences for transport are discussed.

• Received 4 June 2010

DOI:https://doi.org/10.1103/PhysRevLett.105.156801