Well-defined plateaus of the conductance in two-terminal device of nonsuspended graphene

Quantized conductance, reflecting the half-integer quantum Hall effect in a non-suspended single-layer graphene, was clearly observed in a two-terminal device at 2 K and 8 T, particularly at ±2e²/h and ±6e²/h. Dependence of the conductance quantization upon temperature and the magnetic field strength was systematically investigated. In the case of v = +2, the quantized behavior was discernable even at 180 K. Resistance of Dirac point decreased linearly with decrease of temperature and increases below 20 K, implying the behavior of quantum Hall insulator at high magnetic field.