Quasi-flat plasmonic bands in twisted bilayer graphene
| Autor: | Stauber, T., Kohler, H. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Nano Lett. 16, 6844-6849 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1021/acs.nanolett.6b02587 |
| Popis: | The charge susceptibility of twisted bilayer graphene is investigated in the Dirac cone, respectively random-phase approximation. For small enough twist angles $\theta\lesssim 2^\circ$ we find weakly Landau damped interband plasmons, i.~e., collective excitonic modes which exist in the undoped material, with an almost constant energy dispersion. In this regime, the loss function can be described as a Fano resonance and we argue that these excitations arise from the interaction of quasi-localised states with the incident light field. These predictions can be tested by nano-infrared imaging and possible applications include a "perfect" lens without the need of left-handed materials. Comment: 11 pages, 9 figures |
| Databáze: | arXiv |
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