Spin excitation in nano-graphite ribbons with zigzag edges

2020-01-12 19:04:40

excitation exchange Japan Hamiltonian zigzag

责任者: Yoshioka, H. 单位: Dept. of Phys., Nara Womens Univ., Japan 来源出处: Journal of the Physical Society of Japan(J. Phys. Soc. Jpn. (Japan)),Sept. 2003,72(9):2145-8 摘要: Spin excitation in a nano-graphite ribbon with zigzag edges is investigated theoretically. Due to the strongly localized nature of the states near the Fermi energy, the effective Hamiltonian for the low-energy physics is given by the Heisenberg Hamiltonian with the nearest neighbor exchange coupling. The action corresponding to the effective Hamiltonian is mapped to that of the O(3) nonlinear sigma model. It is shown that the spin excitation has a gap when the number of the zigzag lines is even, whereas the excitation becomes gapless in the case of an odd number of zigzag lines 关键词: exchange interactions (electron);Fermi level;graphite;localised states;nanostructured materials;spin dynamics;spin excitation;nanographite ribbon;zigzag edge;strongly localized states;Fermi energy;Heisenberg Hamiltonian;nearest neighbor exchange coupling;nonlinear sigma model;C