Landau levels in bulk graphite by Raman spectroscopy

The electronic Raman scattering of bulk graphite at zero magnetic field reveals a structureless signal characteristic of a metal. For B greater than or similar to 2 T, several peaks at energies scaling linearly with magnetic field were observed and ascribed to transitions from the lowest energy Landau level(s) [LL(s)] to excited states belonging to the same ladder. The LLs are equally (unequally) spaced for high (low) quantum numbers, being consistent with the LL sequence from massive chiral fermions [m(*)=0.033(2)m(e)] with Berry's phase 2 pi found in graphene bilayers. These results provide spectroscopic evidence that some of the physics recently revealed by graphene multilayers is also shared by bulk graphite.