- 著者
- Otani Minoru Takagi Yoshiteru Koshino Mikito Okada Susumu
- 出版者
- American Institute of Physics
- 雑誌
- Applied physics letters (ISSN:00036951)
- 巻号頁・発行日
- vol.96, no.24, pp.242504, 2010-06
- 被引用文献数
- 25
Based on first-principle total-energy calculations, we have found that by applying an external electric field it is possible to control the magnetic state of graphite thin film with the rhombohedral stacking arrangement. When exposed to a moderate electric field normal to the film, the surface of a thin film of rhombohedral graphite undergoes a magnetic phase transition from the antiferromagnetic state to the ferromagnetic state. The polarized electron spin is primarily distributed in the bottommost layer of the film, which forms the interface with the negative electrode. The amount of polarized electron spin is calculated to be 0.067 μB/nm2. The ferromagnetic ordering with the characteristic distribution of the polarized electron spin opens the possibility of using graphite thin films in electronic devices with spin degree of freedom.
- 著者
- Takagi Yoshiteru Okada Susumu
- 出版者
- American Physical Society
- 雑誌
- Physical review B (ISSN:10980121)
- 巻号頁・発行日
- vol.84, no.3, pp.035406, 2011-07
- 被引用文献数
- 9 7
We investigated the electronic structure of semiconducting single-walled carbon nanotubes (CNTs) adsorbed on the (111) surfaces of Au, Ag, Pt, and Pd and on the (0001) surfaces of Mg by first-principles calculations. Our calculations show that the electronic structure of the CNTs adsorbed on the metal surfaces strongly depends on the metal species. We found that on Pd surfaces, the characteristic one-dimensional electronic structure of the CNTs is totally disrupted by the strong hybridization between the π state of the CNTs and the d state of the Pd surfaces. In sharp contrast, on the Au surfaces, the CNTs retain the one-dimensional properties of their electronic structure. The distribution of the total valence charge of the CNTs on the Pd surfaces also shows a strong covalent nature between the CNTs and the surfaces. Our calculations show the importance of metal electrodes in designing CNT electronic devices.