It is widely believed that carrier-density inhomogeneities ("electron-hole puddles") in single-layer graphene on a substrate like quartz are due to charged impurities located close to the graphene sheet. Here we demonstrate by using a Kohn-Sham-Dirac density-functional scheme that corrugations in a real sample are sufficient to determine electron-hole puddles on length scales that are larger than the spatial resolution of state-of-the-art scanning tunneling microscopy.
@article{arxiv.1111.6280,
title = {Electron-hole puddles in the absence of charged impurities},
author = {Marco Gibertini and Andrea Tomadin and Francisco Guinea and Mikhail I. Katsnelson and Marco Polini},
journal= {arXiv preprint arXiv:1111.6280},
year = {2012}
}