We calculate the lowest-order quantum-interference correction to the density of states (DOS) of weaklydisordered two-dimensional (2D) tight-binding square lattices around half filling. The impurities are assumed to be...We calculate the lowest-order quantum-interference correction to the density of states (DOS) of weaklydisordered two-dimensional (2D) tight-binding square lattices around half filling. The impurities are assumed to be randomly distributed on small fractions of the sites, and have a strong potential yielding a unitary-limit scattering. In addition to the usual diffusive modes in the retarded-advanced channel, there appear diffusive π modes in the retardedretarded (or advanced-advanced) channel due to the existence of particle-hole symmetry. It is found that the π-mode diffuson gives rise to a logarithmic suppression to the DOS near the band center, which prevails over the positive correction contributed by π-mode cooperon. As a result, the DOS is subject to a negative total correction. This result is qualitatively different from the divergent behavior of the DOS at the band center predicted previously for disordered 2D two-sublattice models with the particle-hole symmetry.展开更多
O434.19 2001064143二维点阵的软X射线衍射实验研究=Experimentalstudy on soft X—ray diffraction of a two-di-mensionalarray[刊,中]/徐向东,洪义麟,霍同林,蒋诗平,单晓斌,杨绍光,付绍军(中国科技大学国家同步辐射实验室.安徽,合肥(...O434.19 2001064143二维点阵的软X射线衍射实验研究=Experimentalstudy on soft X—ray diffraction of a two-di-mensionalarray[刊,中]/徐向东,洪义麟,霍同林,蒋诗平,单晓斌,杨绍光,付绍军(中国科技大学国家同步辐射实验室.安徽,合肥(230029))∥光学学报.—2000,展开更多
文摘We calculate the lowest-order quantum-interference correction to the density of states (DOS) of weaklydisordered two-dimensional (2D) tight-binding square lattices around half filling. The impurities are assumed to be randomly distributed on small fractions of the sites, and have a strong potential yielding a unitary-limit scattering. In addition to the usual diffusive modes in the retarded-advanced channel, there appear diffusive π modes in the retardedretarded (or advanced-advanced) channel due to the existence of particle-hole symmetry. It is found that the π-mode diffuson gives rise to a logarithmic suppression to the DOS near the band center, which prevails over the positive correction contributed by π-mode cooperon. As a result, the DOS is subject to a negative total correction. This result is qualitatively different from the divergent behavior of the DOS at the band center predicted previously for disordered 2D two-sublattice models with the particle-hole symmetry.
文摘O434.19 2001064143二维点阵的软X射线衍射实验研究=Experimentalstudy on soft X—ray diffraction of a two-di-mensionalarray[刊,中]/徐向东,洪义麟,霍同林,蒋诗平,单晓斌,杨绍光,付绍军(中国科技大学国家同步辐射实验室.安徽,合肥(230029))∥光学学报.—2000,