Indirect Coupling Between Localized Magnetic Moments in Zero-Dimensional Graphene Nanostructures (Quantum Dots) |
| K. Szałowski
Department of Solid State Physics, Faculty of Physics and Applied Informatics, University of Łódź, Pomorska 149/153, PL 90-236 Łódź, Poland |
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| The indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling between on-site magnetic impurities is studied for two kinds of graphene nanoflakes consisting of approximately 100 carbon atoms, posessing either zigzag or armchair edge. The tight-binding Hamiltonian with Hubbard term is used in non-perturbative calculations of coupling between the impurities, placed at the edge of the structure. In general, for zigzag-edged nanoflakes a pronounced coupling robust against charge doping is found, while for armchair-edged structures the interaction is weaker and much more sensitive to charge doping. Also the distance dependence of indirect exchange differs significantly for both edge forms. |
DOI: 10.12693/APhysPolA.126.236 PACS numbers: 75.30.Hx, 75.75.-c, 73.22.Pr |