Nemec, Norbert and Cuniberti, Gianaurelio
Hofstadter butterflies of bilayer graphene.
Physical Review B 75, 201404(R).
Other URL: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRBMDO000075000020201404000001&idtype=cvips&gifs=yes
We calculate the electronic spectrum of bilayer graphene in perpendicular magnetic fields non-perturbatively. To accomodate arbitrary displacements between the two layers, we apply a periodic gauge based on singular flux vortices of phase . The resulting Hofstadter-like butterfly plots show a reduced symmetry, depending on the relative position of the two layers against each other. The split of the zero-energy relativistic Landau level differs by one order of magnitude between Bernal- and non-Bernal stacking.