Metal-insulator transition in anisotropic systems with both diagonal and spin-orientation-dependent off-diagonal disorder
Wen-Sheng Liu; Shi-Jie Xiong; Wen-Sheng Liu; Department of Physics and Solid Microstructure Laboratory, Nanjing University, Nanjing 210093, People's Republic of China; Shi-Jie Xiong; Department of Physics and Solid Microstructure Laboratory, Nanjing University, Nanjing 210093, People's Republic of China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1999-02-15
Аннотация:
The localization behaviour of the anisotropic extended double-exchange model with both diagonal and spin-orientation-dependent off-diagonal disorder is investigated using the transfer-matrix method. The anisotropy is described by different in-plane and inter-plane hopping integrals. By using a mean-field distribution of the spin orientation, the localization length of electrons is calculated as a function of temperature. It is found that the metal-insulator transition temperature t<sub>MIT</sub> of the system increases with decreasing degree of anisotropy γ. On the insulating side, the localization length for t close to t<sub>MIT</sub> varies as . We also calculate the value of ν for various γ-values. The comparison of the results obtained and the experimental measurements for the layered mixed-valence Mn oxides is discussed.
119.3Кб