Tunneling characteristics of graphene
  Negative differential conductance and tunneling characteristics of two-terminal graphene devices are observed before and after electric breakdown, respectively. The former is caused by the strong scattering under a high E-field, and the latter is due to the appearance of a tunneling barrier in graphene channel induced by a structural transformation from crystalline graphene to disordered graphene because of the breakdown. Using Raman spectroscopy and imaging, the presence of non-uniform disordered graphene is confirmed. A memory switching effect of 100000% ON/OFF ratio is demonstrated in the tunneling regime which can be employed in various applications. 
Young Jun Shin, Gopinadhan Kalon, Jaesung Son, Jae Hyun Kwon, Jing   Niu, Charanjit S. Bhatia, Gengchiau Liang, and Hyunsoo Yang
cond-mat.mes-hall cond-mat.mtrl-sci