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L. Chizhova, F. Libisch, J. Burgdörfer:
"Graphene quantum dots with superlattice potential in the presence of a magnetic field";
Poster: 1st Erwin Schrödinger Symposium 2014 of the Erwin Schrödinger Society for Nanosciences "Two Dimensional Nanostructures", Naturhistorische Museum; 26.11.2014 - 28.11.2014.

In our recent work [1] we studied the influence of a boron nitride substrate on the density of states of a graphene flake in the presence of a perpendicular magnetic field. In several experiments (for example [2]) it was found that the boron nitride induces an additional periodic moire potential resulting from the van der Waals interaction between graphene and the substrate. The additional periodic superlattice potential is expected to create replicas of the original Dirac cone due to zone folding. Besides, each Landau level at high magnetic field acquires a Hofstadter butterfly structure. The interplay between the different Landau levels creates a complicated pattern in the density of states. Our tight-binding simulations reveal an unexpected coexistence of relativistic (for the main Dirac cone) and non-relativistic (at the replicas) Landau level structures. An unambiguous hallmark of the Dirac cone is the presence of the zeroth Landau level and its butterfly which is missing at the replicas in our calculations and in the experiment [3].

[1] L.A. Chizhova, F.Libisch, J.Burgdörfer, PRB, 90, 165404, 2014
[2] M. Yankowitz, et al.J. Xue, D,Cormode, et al. Nat Phys, 8, 382, 2012
[3] G.L.Yu, R.V. Gorbachev, J.S. Tu, et al. Nat Phys, 10, 525, 2014