First-principles study of carrier-induced ferromagnetism in bilayer and multilayer zigzag graphene nanoribbons

金沢大学理工研究域数物科学系We studied magnetism in bilayer and multilayer zigzag graphene nanoribbons (ZGNRs) through first-principles density functional theory calculations. We found that the magnetic ground state of bilayer ZGNRs is the C-type antiferromagnetic (AFM) state, which is the AFM order between intraplane-edge carbon atoms and ferromagnetic (FM) order between interplane edge carbon atoms. In the cases of infinitely stacked multilayer ZGNRs, i.e., zigzag graphite nanoribbons, the C-type AFM state is also the most stable. By carrier doping, we found that the magnetic ground state changed from the C-AFM state to the FM state and, thus, realized two-dimensional FM surface (edge) states of graphite with a metallic conductivity.Part of this research has been funded by the MEXT HPCI Strategic Program. This work was partly supported by Grants-in-Aid for Scientific Research (Nos. 21560030, 22016003, 25104714, 25790007, and 25390008) from the JSPS. The computations in this research have been performed using the supercomputers at the ISSP, University of Tokyo, the RCCS, Okazaki National Institute, and the IMR, Tohoku University.Embargo Period 12 month