Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers
We report high magnetic field scanning tunneling microscopy and Landau level spectroscopy of twisted graphene layers grown by chemical vapor deposition. For twist angles exceeding ∼3° the low energy carriers exhibit Landau level spectra characteristic of massless Dirac fermions. Above 20° the layers...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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American Physical Society
2011
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| Online Access: | http://hdl.handle.net/1721.1/65391 https://orcid.org/0000-0003-0551-1208 |
| _version_ | 1811095783833862144 |
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| author | Luican, A. Li, Guohong Reina, Alfonso Kong, Jing Nair, R. R. Novoselov, Kostya S. Geim, A. K. Andrei, E. Y. |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Luican, A. Li, Guohong Reina, Alfonso Kong, Jing Nair, R. R. Novoselov, Kostya S. Geim, A. K. Andrei, E. Y. |
| author_sort | Luican, A. |
| collection | MIT |
| description | We report high magnetic field scanning tunneling microscopy and Landau level spectroscopy of twisted graphene layers grown by chemical vapor deposition. For twist angles exceeding ∼3° the low energy carriers exhibit Landau level spectra characteristic of massless Dirac fermions. Above 20° the layers effectively decouple and the electronic properties are indistinguishable from those in single-layer graphene, while for smaller angles we observe a slowdown of the carrier velocity which is strongly angle dependent. At the smallest angles the spectra are dominated by twist-induced van Hove singularities and the Dirac fermions eventually become localized. An unexpected electron-hole asymmetry is observed which is substantially larger than the asymmetry in either single or untwisted bilayer graphene. |
| first_indexed | 2024-09-23T16:27:48Z |
| format | Article |
| id | mit-1721.1/65391 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:27:48Z |
| publishDate | 2011 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/653912022-09-29T19:53:30Z Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers Luican, A. Li, Guohong Reina, Alfonso Kong, Jing Nair, R. R. Novoselov, Kostya S. Geim, A. K. Andrei, E. Y. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Department of Materials Science and Engineering Kong, Jing Reina, Alfonso Kong, Jing We report high magnetic field scanning tunneling microscopy and Landau level spectroscopy of twisted graphene layers grown by chemical vapor deposition. For twist angles exceeding ∼3° the low energy carriers exhibit Landau level spectra characteristic of massless Dirac fermions. Above 20° the layers effectively decouple and the electronic properties are indistinguishable from those in single-layer graphene, while for smaller angles we observe a slowdown of the carrier velocity which is strongly angle dependent. At the smallest angles the spectra are dominated by twist-induced van Hove singularities and the Dirac fermions eventually become localized. An unexpected electron-hole asymmetry is observed which is substantially larger than the asymmetry in either single or untwisted bilayer graphene. United States. Dept. of Energy (DE-FG02- 99ER45742) National Science Foundation (U.S.) (DMR 0845358) National Science Foundation (U.S.) (DMR-0906711) United States. Office of Naval Research (MURI N00014-09-1-1063) 2011-08-26T14:19:39Z 2011-08-26T14:19:39Z 2011-03 2010-10 Article http://purl.org/eprint/type/JournalArticle 0031-9007 http://hdl.handle.net/1721.1/65391 Luican, A. et al. “Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers.” Physical Review Letters 106.12 (2011) © 2011 American Physical Society https://orcid.org/0000-0003-0551-1208 en_US http://dx.doi.org/10.1103/PhysRevLett.106.126802 Physical Review Letters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Luican, A. Li, Guohong Reina, Alfonso Kong, Jing Nair, R. R. Novoselov, Kostya S. Geim, A. K. Andrei, E. Y. Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title | Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title_full | Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title_fullStr | Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title_full_unstemmed | Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title_short | Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers |
| title_sort | single layer behavior and its breakdown in twisted graphene layers |
| url | http://hdl.handle.net/1721.1/65391 https://orcid.org/0000-0003-0551-1208 |
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