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arXiv · 1012.0374

Imaging charge density fluctuations in graphene using Coulomb blockade spectroscopy

A. Deshpande·W. Bao·H. Zhang·Z. Zhao·C. N. Lau·B. J. LeRoy
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Abstract

Using scanning tunneling microscopy, we have imaged local charge density fluctuations in monolayer graphene. By placing a small gold nanoparticle on the end of the STM tip, a charge sensor is created. By raster scanning the tip over the surface and using Coulomb blockade spectroscopy, we map the local charge on the graphene. We observe a series of electron and hole doped puddles with a characteristic length scale of about 20 nm. Theoretical calculations for the correlation length of the puddles based on the number of impurities are in agreement with our measurements.

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A. Deshpande, W. Bao, H. Zhang, Z. Zhao, C. N. Lau, B. J. LeRoy. 2010-12-03. Imaging charge density fluctuations in graphene using Coulomb blockade spectroscopy. https://doi.org/10.1103/physrevb.83.155409

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