  Recent experiments on suspended graphene layers have indicated the crucial
role of carrier mobility in the competition between Laughlin collective state
and insulating state, probably of Wigner-crystal-type. Moreover, the fractional
quantum Hall effect (FQHE) in graphene has been observed at a low carrier
density where the interaction is reduced as a result of particles dilution.
This suggests that the interaction may not be as important in the triggering of
FQHE as expected based on the standard formulation of the composite fermions
model. Here, the topological arguments are presented to explain these novel
features of the FQHE in graphene and, the triggering role of carriers mobility
in particular.
