The role of charge traps in inducing hysteresis: capacitance - voltage   measurements on top gated bilayer graphene
  Understanding the origin of hysteresis in the channel resistance from top gated graphene transistors is important for transistor applications. Capacitance - voltage measurements across the gate oxide on top gated bilayer graphene show hysteresis with a charging and discharging time constant of ~100 {\mu}s. However, the measured capacitance across the graphene channel does not show any hysteresis, but shows an abrupt jump at a high channel voltage due to the emergence of an order, indicating that the origin of hysteresis between gate and source is due to charge traps present in the gate oxide and graphene interface. 
Gopinadhan Kalon, Young Jun Shin, Viet Giang Truong, Alan Kalitsov,   and Hyunsoo Yang
cond-mat.mtrl-sci cond-mat.mes-hall