Magnetotransport in graphene on silicon side of SiC

TL;DR

This study investigates the magnetotransport properties of graphene on silicon carbide, revealing the coexistence of two distinct carrier groups with different densities, a novel finding for this material system.

Contribution

It demonstrates the presence of two parallel conducting channels with different carrier densities in graphene on SiC, a previously unreported phenomenon.

Findings

Identification of two periods of magneto-oscillations indicating two conduction channels.

Channels are formed by high-density and low-density Dirac carriers.

Semi-quantitative agreement with model calculations supports the findings.

Abstract

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