We study transport phenomena in clean suspended graphene at the Dirac point. We focus on the effects arising due to the so-called crumpling transition (transition from the crumpled to flat phase of the graphene membrane) and demonstrate that renormalization of out-of-plane vibration modes in course of this transition leads to dramatic change of the electron transport properties. We find that the conductivity of graphene scales with the temperature as T^-η, where η is the critical exponent of the crumpling transition (equal to 0.7 according to numerical studies). We also discuss the behavior of conductivity away from the Dirac point and compare our predictions with available experimental data.

Page created on February 14, 2013.