Impurity scattering in carbon nanotubes-absence of backscattering

2019-10-19 16:25:20

The carbon element diagonal Japan

责任者: Ando, T.;Nakanishi, T. 单位: Inst. of Solid State Phys., Tokyo Univ., Japan 来源出处: Journal of the Physical Society of Japan(J. Phys. Soc. Jpn. (Japan)),1998/05/,67(5):1704-13 摘要: The effective potential of an impurity in a k·p scheme is derived for a two-dimensional graphite sheet. When the potential range is smaller than the lattice constant, it has an off-diagonal matrix element between K and K points comparable to the diagonal element. With the increase of the range, this off-diagonal element decreases rapidly and the diagonal element for envelopes at A and B sites becomes identical. The crossover between these two regimes occurs around the range smaller than the lattice constant. In the latter regime, backscattering between states with +k and -k vanishes identically for the bands crossing the Fermi level in the absence of a magnetic field, leading to an extremely large conductivity. The absence of the backscattering disappears in magnetic fields, giving rise to a huge positive magnetoresistance 关键词: carbon;Fermi level;impurity scattering;k.p calculations;magnetoresistance;nanostructured materials;carbon nanotubes;impurity scattering;k·p scheme;two-dimensional graphite sheet;off-diagonal matrix element;lattice constant;positive magnetoresistance;C