par Goldman, Nathan 
Référence Journal of Physics. B, Atomic Molecular and Optical Physics, 42, page (055302)
Publication Publié, 2009
Référence Journal of Physics. B, Atomic Molecular and Optical Physics, 42, page (055302)
Publication Publié, 2009
Article révisé par les pairs
| Résumé : | In this work, we report original properties inherent to independent particles subjected to a magnetic field by emphasizing the existence of regular structures in the energy spectrum's outline. We show that this fractal curve, the well-known Hofstadter butterfly's outline, is associated with a specific sequence of Chern numbers that correspond to the quantized transverse conductivity. Indeed the topological invariant that characterizes the fundamental energy band depicts successive stairways as the magnetic flux varies. Moreover each stairway is shown to be labelled by another Chern number which measures the charge transported under displacement of the periodic potential. We put forward the universal character of these properties by comparing the results obtained for the square and the honeycomb geometries. © 2009 IOP Publishing Ltd. |
