Insulating behavior in metallic bilayer graphene: Interplay between density inhomogeneity and temperature

We investigate bilayer graphene transport in the presence of electron-hole puddles induced by long-range charged impurities in the environment. We explain the insulating behavior observed in the temperature-dependent conductivity of low mobility bilayer graphene using an analytic statistical theory taking into account the non-mean-field nature of transport in the highly inhomogeneous density and potential landscape. We find that the puddles can induce, even far from the charge neutrality point, a coexisting metallic and insulating transport behavior due to the random local activation gap in the system.