Multilayer graphene shows intrinsic resistance peaks in the carrier density dependence: experiments in tetra- and hexlayer graphene

Since the advent of graphene, a variety of studies have been done 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 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. Similar but different peak structures were observed in six-layer graphene. 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. ( Sci. Rep. 8, 13992 (2018). DOI: 10.1038/s41598-018-32214-7)