Tunneling Spectroscopy of Graphene-Boron Nitride Heterostructures
  We report on the fabrication and measurement of a graphene tunnel junction using hexagonal-boron nitride as a tunnel barrier between graphene and a metal gate. The tunneling behavior into graphene is altered by the interactions with phonons and the presence of disorder. We extract prop- erties of graphene and observe multiple phonon-enhanced tunneling thresholds. Finally, differences in the measured properties of two devices are used to shed light on mutually-contrasting previous results of scanning tunneling microscopy in graphene. 
F. Amet, J. R. Williams, A. G. F. Garcia, M. Yankowitz, K. Watanabe,   T. Taniguchi, and D. Goldhaber-Gordon
cond-mat.mes-hall