Coulomb drag between in-plane graphene double ribbons and the impact of the dielectric constant
With recent developments in the search for novel device ideas, understanding electron-electron interaction in low dimensional systems is of particular interest. Coulomb drag measurements can provide critical insights in this context. In this article, we present a novel planar graphene double ribbon structure that shows for the first time that Coulomb drag is observable in two adjacent monolayer ribbons in the same plane at room temperature. Moreover, our planar devices enable experimentally study of the impact of the dielectric constant on Coulomb drag which is difficult to explore in the typically used double layer graphene structures. Our experimental findings indicate in particular that the drag resistance is proportional to the dielectric constant (ε) and does not, as recently reported, show an increasing trend of interaction strength for small ε-values. In fact, we find that the drag resistance follows approximately an ε 1.2-dependence. The exponent of “1.2” is consistent with the theory considering the carrier concentration in our samples, and positions our results in between the weak and strong coupling limits.
KeywordsCoulomb drag graphene ribbon dielectric scattering electron-electron interactions
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- Chen, H. Y.; Appenzeller, J. Complementary-type graphene inverters operating at room-temperature Device Res. Conf. 2011, 33–34.Google Scholar
- The voltage detection unit has a very large impedance (10 Mohm) to ground and hence the drag channel (< 150 kohm) can be considered floatingGoogle Scholar
- Since our C bg is quite small (90 nm SiO2), contributions from the quantum capacitance can be ignored for carrier concentrations > 1011 cm-2.Google Scholar
- In our quantitative comparison, a minor difference in temperature (295 K in this work and 240 K in Ref. ) has not been included.Google Scholar
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