Magnetotransport in graphene on silicon side of SiC

摘要

We have studied the transport properties of graphene grown on silicon side ofSiC. Samples under study have been prepared by two different growth methods intwo different laboratories. Magnetoresistance and Hall resistance have beenmeasured at temperatures between 4 and 100 K in resistive magnet in magneticfields up to 22 T. In spite of differences in sample preparation, the fielddependence of resistances measured on both sets of samples exhibits two periodsof magneto-oscillations indicating two different parallel conducting channelswith different concentrations of carriers. The semi-quantitative agreement withthe model calculation allows for conclusion that channels are formed byhigh-density and low-density Dirac carriers. The coexistence of two differentgroups of carriers on the silicon side of SiC was not reported before.