Mapping Dirac quasiparticles near a single Coulomb impurity on graphene
The response of Dirac fermions to a Coulomb potential is predicted to differ significantly from how non-relativistic electrons behave in traditional atomic and impurity systems. Surprisingly, many key theoretical predictions for this ultra-relativistic regime have not been tested. Graphene, a two-di...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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Nature Publishing Group
2015
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| Online Access: | http://hdl.handle.net/1721.1/98222 https://orcid.org/0000-0002-4268-731X |
| _version_ | 1826205958714425344 |
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| author | Wang, Yang Brar, Victor W. Shytov, Andrey V. Wu, Qiong Regan, William Tsai, Hsin-Zon Zettl, Alex Crommie, Michael F. Levitov, Leonid |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Wang, Yang Brar, Victor W. Shytov, Andrey V. Wu, Qiong Regan, William Tsai, Hsin-Zon Zettl, Alex Crommie, Michael F. Levitov, Leonid |
| author_sort | Wang, Yang |
| collection | MIT |
| description | The response of Dirac fermions to a Coulomb potential is predicted to differ significantly from how non-relativistic electrons behave in traditional atomic and impurity systems. Surprisingly, many key theoretical predictions for this ultra-relativistic regime have not been tested. Graphene, a two-dimensional material in which electrons behave like massless Dirac fermions, provides a unique opportunity to test such predictions. Graphene’s response to a Coulomb potential also offers insight into important material characteristics, including graphene’s intrinsic dielectric constant, which is the primary factor determining the strength of electron–electron interactions in graphene. Here we present a direct measurement of the nanoscale response of Dirac fermions to a single Coulomb potential placed on a gated graphene device. Scanning tunnelling microscopy was used to fabricate tunable charge impurities on graphene, and to image electronic screening around them for a Q = +1|e| charge state. Electron-like and hole-like Dirac fermions were observed to respond differently to a Coulomb potential. Comparing the observed electron–hole asymmetry to theoretical simulations has allowed us to test predictions for how Dirac fermions behave near a Coulomb potential, as well as extract graphene’s intrinsic dielectric constant: ε[subscript g] = 3.0±1.0. This small value of ε[subscript g] indicates that electron–electron interactions can contribute significantly to graphene properties. |
| first_indexed | 2024-09-23T13:21:45Z |
| format | Article |
| id | mit-1721.1/98222 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:21:45Z |
| publishDate | 2015 |
| publisher | Nature Publishing Group |
| record_format | dspace |
| spelling | mit-1721.1/982222022-09-28T13:38:56Z Mapping Dirac quasiparticles near a single Coulomb impurity on graphene Wang, Yang Brar, Victor W. Shytov, Andrey V. Wu, Qiong Regan, William Tsai, Hsin-Zon Zettl, Alex Crommie, Michael F. Levitov, Leonid Massachusetts Institute of Technology. Department of Physics Levitov, Leonid The response of Dirac fermions to a Coulomb potential is predicted to differ significantly from how non-relativistic electrons behave in traditional atomic and impurity systems. Surprisingly, many key theoretical predictions for this ultra-relativistic regime have not been tested. Graphene, a two-dimensional material in which electrons behave like massless Dirac fermions, provides a unique opportunity to test such predictions. Graphene’s response to a Coulomb potential also offers insight into important material characteristics, including graphene’s intrinsic dielectric constant, which is the primary factor determining the strength of electron–electron interactions in graphene. Here we present a direct measurement of the nanoscale response of Dirac fermions to a single Coulomb potential placed on a gated graphene device. Scanning tunnelling microscopy was used to fabricate tunable charge impurities on graphene, and to image electronic screening around them for a Q = +1|e| charge state. Electron-like and hole-like Dirac fermions were observed to respond differently to a Coulomb potential. Comparing the observed electron–hole asymmetry to theoretical simulations has allowed us to test predictions for how Dirac fermions behave near a Coulomb potential, as well as extract graphene’s intrinsic dielectric constant: ε[subscript g] = 3.0±1.0. This small value of ε[subscript g] indicates that electron–electron interactions can contribute significantly to graphene properties. United States. Office of Naval Research. Multidisciplinary University Research Initiative (Award N00014-09-1-1066) United States. Dept. of Energy. Office of Science (Contract DE-AC02-05CH11231) National Science Foundation (U.S.) (Award DMR-0906539) 2015-08-25T18:44:35Z 2015-08-25T18:44:35Z 2012-07 2012-02 Article http://purl.org/eprint/type/JournalArticle 1745-2473 1745-2481 http://hdl.handle.net/1721.1/98222 Wang, Yang, Victor W. Brar, Andrey V. Shytov, Qiong Wu, William Regan, Hsin-Zon Tsai, Alex Zettl, Leonid S. Levitov, and Michael F. Crommie. “Mapping Dirac Quasiparticles Near a Single Coulomb Impurity on Graphene.” Nature Physics 8, no. 9 (July 29, 2012): 653–657. https://orcid.org/0000-0002-4268-731X en_US http://dx.doi.org/10.1038/nphys2379 Nature Physics Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Nature Publishing Group arXiv |
| spellingShingle | Wang, Yang Brar, Victor W. Shytov, Andrey V. Wu, Qiong Regan, William Tsai, Hsin-Zon Zettl, Alex Crommie, Michael F. Levitov, Leonid Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title | Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title_full | Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title_fullStr | Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title_full_unstemmed | Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title_short | Mapping Dirac quasiparticles near a single Coulomb impurity on graphene |
| title_sort | mapping dirac quasiparticles near a single coulomb impurity on graphene |
| url | http://hdl.handle.net/1721.1/98222 https://orcid.org/0000-0002-4268-731X |
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