Adsorbate-limited conductivity of graphene
  We present a theory of electronic transport in graphene in the presence of randomly placed adsorbates. Our analysis predicts a marked asymmetry of the conductivity about the Dirac point, as well as a negative weak-localization magnetoresistivity. In the region of strong scattering, renormalization group corrections drive the system further towards insulating behavior. These results explain key features of recent experiments, and are validated by numerical transport computations. 
John P. Robinson, Henning Schomerus, Laszlo Oroszlany, Vladimir I.   Fal'ko