Drag resistivity in double-layer gapped graphene structures

We study the frictional drag phenomenon in a double-layer system made of two parallel gapped graphene layers by calculating the Coulomb drag resistivity. The random-phase approximation is employed to determine the polarizability functions of layers and the frequency-dependent dielectric function of the structure. Our computations illustrate that the Coulomb drag resistivity in double-layer gapped graphene systems show some interesting different features, compared to that in other double-layer ones. Coulomb drag resistivity in the system steadily increases as temperature increases but quickly decreases with the increase in interlayer distance. With small interlayer separations, the drag resistivity behaves as a smoothly increasing function of the bandgap. Nevertheless, with sufficiently large separations, the Coulomb drag resistivity increases with small bandgaps but decreases with larger ones. We observe that a finite bandgap has remarkable contributions to the frictional drag phenomenon, therefore it is necessary to take into account this factor in calculations to make better agreements with experimental works.

Automated summary

We studied the frictional drag phenomenon in a double-layer system consisting of two parallel gapped graphene layers by calculating the Coulomb drag resistivity. The Coulomb drag resistivity in double-layer gapped graphene systems shows interesting different features compared to other double-layer systems. The temperature steadily increases the Coulomb drag resistivity in the system, while the interlayer distance quickly decreases it. A finite bandgap has remarkable contributions to the frictional drag phenomenon, and it is necessary to consider this factor in calculations for better agreement with experimental works.