Quantum Hall-like effect in gated four-terminal graphene devices without magnetic field

We investigate the transport properties of a four-terminal graphene device of which two terminals are beneath a pair of reversal top gate voltages. We find there exists quantum Hall-like effect without magnetic field applied. The curve of Hall conductance versus the Fermi energy shows steps, and the disorder can make the steps clearer. The average length of Hall conductance plateaus is of the order meV for the devices with the terminal widths of the order mu m, which is within the scope of the experimental observation. The influences of gate voltage, device dimensions, and dispersion gap are also discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3663625]