Universal scaling of resistivity in bilayer graphene
  We report the temperature dependent electrical transport properties of gated bilayer graphene devices. We see a clear evidence of insulating behavior due to electron-hole charge puddles. The electrical resistivity increases while the mobility decreases with decreasing temperature, a characteristic due to carrier inhomogeneity in graphene. The theoretical fittings using an empirical formula of single electron tunneling indicate that electrical resistivity follows a universal curve with a scaling parameter. The scaling parameter is determined to be a measure of the fluctuations in the electron-hole puddle distribution. 
Kalon Gopinadhan, Young Jun Shin, and Hyunsoo Yang
cond-mat.mtrl-sci cond-mat.mes-hall