  Since the advent of graphene, a variety of studies have been performed to
elucidate its fundamental physics, or to explore its practical applications.
Gate-tunable resistance is one of the most important properties of graphene and
has been studied in 1-3 layer graphene in a number of efforts to control the
band gap to obtain a large on-off ratio. On the other hand, the transport
property of multilayer graphene with more than three layers is less well
understood. Here we show a new aspect of multilayer graphene. We found that
four-layer graphene shows intrinsic peak structures in the gate voltage
dependence of its resistance at zero magnetic field. Measurement of quantum
oscillations in magnetic field confirmed that the peaks originate from the
specific band structure of graphene and appear at the carrier density for the
bottoms of conduction bands and valence bands. The intrinsic peak structures
should generally be observed in AB-stacked multilayer graphene. The present
results would be significant for understanding the physics of graphene and
making graphene FET devices.
