Rickhaus, Peter and Liu, Ming-Hao and Kurpas, Marcin and Kurzmann, Annika and Lee, Yongjin and Overweg, Hiske and Eich, Marius and Pisoni, Riccardo and Tamaguchi, Takashi and Wantanabe, Kenji and Richter, Klaus and Ensslin, Klaus and Ihn, Thomas (2020) The electronic thickness of graphene. SCIENCE ADVANCES, 6 (11): eaay8409. ISSN 2375-2548,
Full text not available from this repository. (Request a copy)Abstract
When two dimensional crystals are atomically close, their finite thickness becomes relevant. Using transport measurements, we investigate the electrostatics of two graphene layers, twisted by theta = 22 degrees such that the layers are decoupled by the huge momentum mismatch between the K and K' points of the two layers. We observe a splitting of the zero-density lines of the two layers with increasing interlayer energy difference. This splitting is given by the ratio of single-layer quantum capacitance over interlayer capacitance C-m and is therefore suited to extract C-m. We explain the large observed value of C-m by considering the finite dielectric thickness d(g) of each graphene layer and determine d(g) approximate to 2.6 angstrom. In a second experiment, we map out the entire density range with a Fabry-Perot resonator. We can precisely measure the Fermi wavelength lambda in each layer, showing that the layers are decoupled. Our findings are reproduced using tight-binding calculations.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | HETEROSTRUCTURES; INTERFERENCE; STATES; DRAG; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Klaus Richter |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 29 Mar 2021 11:38 |
| Last Modified: | 29 Mar 2021 11:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/45014 |
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