Percolation and weak localization in thin discontinuous aluminum films

详细信息    查看全文

• 作者：Yamada ; Kazumasa ; Shinozaki ; Bunjyu ; Kawaguti ; Takasi
• 关键词：Percolation ; Weak localization ; Superconductor ; Magnetoconductance
• 刊名：Physica E
• 出版年：2003
• 出版时间：May, 2003
• 年：2003
• 卷：18
• 期：1-3
• 页码：286-287
• 全文大小：85.8 K

文摘

In order to investigate the crossover from the homogeneous behavior to percolative one for two-dimensional system, the temperature T and magnetic field H dependence of the sheet resistance R_sq have been measured for thin granular aluminum films. In a magnetic field of 5T, the conductance σ decreases with decreasing T as σ=α_Te²/(2π²plankv)lnT+σ₀ due to weak localization effect. The value of α_T decreases when R_sq increases beyond 68kΩ. In the network which does not contain loops smaller than the phase relaxation length, weak localization effect is considered to be suppressed. We have obtained the anomalous T-dependent diffusion constant D from the analysis of the magnetoconductance above T_C with use of the fitting parameter D(T). These behaviors can be explained qualitatively by a model of scaling law for percolation.