Ambipolar bistable switching effect of graphene
  Reproducible current hysteresis is observed in graphene with a back gate structure in a two-terminal configuration. By applying a back gate bias to tune the Fermi level, an opposite sequence of switching with the different charge carriers, holes and electrons, is found. The charging and discharging effect is proposed to explain this ambipolar bistable hysteretic switching. To confirm this hypothesis, one-level transport model simulations including charging effect are performed and the results are consistent with our experimental data. Methods of improving the ON/OFF ratio of graphene resistive switching are suggested. 
Young Jun Shin, Jae Hyun Kwon, Gopinadhan Kalon, Kai-Tak Lam,   Charanjit S. Bhatia, Gengchiau Liang, and Hyunsoo Yang
cond-mat.mes-hall cond-mat.mtrl-sci