Bandstructure of Graphene and Carbon Nanotubes: An ... - Physics

8 APPENDIX 14
8 Appendix
E/γ 1
E/γ 1
0
(9,0)
(11,0)
E g
E/γ 1
E/γ 1
(10,0)
Eg
(12,0)
Figure 9: One-dimensional bandstructures of different zig-zag tubes. Only the ‘upper’ part for E> 0
is shown.
The occurence of bands with no dispersion at all (infinite mass !) may appear surprising. But
looking again at the surface of the 2d bandstructure of graphene, one can indeed see directions
for which E = const, see Fig. 10.