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arXiv · 1002.1268

Electron density distribution and screening in rippled graphene sheets

Marco Gibertini·Andrea Tomadin·Marco Polini·A. Fasolino·M. I. Katsnelson
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Abstract

Single-layer graphene sheets are typically characterized by long-wavelength corrugations (ripples) which can be shown to be at the origin of rather strong potentials with both scalar and vector components. We present an extensive microscopic study, based on a self-consistent Kohn-Sham-Dirac density-functional method, of the carrier density distribution in the presence of these ripple-induced external fields. We find that spatial density fluctuations are essentially controlled by the scalar component, especially in nearly-neutral graphene sheets, and that in-plane atomic displacements are as important as out-of-plane ones. The latter fact is at the origin of a complicated spatial distribution of electron-hole puddles which has no evident correlation with the out-of-plane topographic corrugations. In the range of parameters we have explored, exchange and correlation contributions to the Kohn-Sham potential seem to play a minor role.

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Marco Gibertini, Andrea Tomadin, Marco Polini, A. Fasolino, M. I. Katsnelson. 2010-02-05. Electron density distribution and screening in rippled graphene sheets. https://doi.org/10.1103/physrevb.81.125437

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