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arXiv · 1705.06077

Spatially resolving density-dependent screening around a single charged atom in graphene

Dillon Wong·Fabiano Corsetti·Yang Wang·Victor W. Brar·Hsin-Zon Tsai·Qiong Wu·Roland K. Kawakami·Alex Zettl·Arash A. Mostofi·Johannes Lischner·Michael F. Crommie
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Abstract

Electrons in two-dimensional graphene sheets behave as interacting chiral Dirac fermions and have unique screening properties due to their symmetry and reduced dimensionality. By using a combination of scanning tunneling spectroscopy (STM/STS) measurements and theoretical modeling we have characterized how graphene's massless charge carriers screen individual charged calcium atoms. A back-gated graphene device configuration has allowed us to directly visualize how the screening length for this system can be tuned with carrier density. Our results provide insight into electron-impurity and electron-electron interactions in a relativistic setting with important consequences for other graphene-based electronic devices.

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Dillon Wong, Fabiano Corsetti, Yang Wang, Victor W. Brar, Hsin-Zon Tsai, Qiong Wu, Roland K. Kawakami, Alex Zettl, Arash A. Mostofi, Johannes Lischner, Michael F. Crommie. 2017-05-17. Spatially resolving density-dependent screening around a single charged atom in graphene. https://doi.org/10.1103/physrevb.95.205419

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