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arXiv · 1512.05304

Charge Puddles in Graphene Near the Dirac Point

S. Samaddar·I. Yudhistira·S. Adam·H. Courtois·C. B. Winkelmann
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Abstract

The charge carrier density in graphene on a dielectric substrate such as SiO$_2$ displays inhomogeneities, the so-called charge puddles. Because of the linear dispersion relation in monolayer graphene, the puddles are predicted to grow near charge neutrality, a markedly distinct property from conventional two-dimensional electron gases. By performing scanning tunneling microscopy/spectroscopy on a mesoscopic graphene device, we directly observe the puddles' growth, both in spatial extent and in amplitude, as the Dirac point is approached. Self-consistent screening theory provides a unified description of both the macroscopic transport properties and the microscopically observed charge disorder.

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S. Samaddar, I. Yudhistira, S. Adam, H. Courtois, C. B. Winkelmann. 2015-12-16. Charge Puddles in Graphene Near the Dirac Point. https://doi.org/10.1103/physrevlett.116.126804

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