Scaling Functions Quantum Hall Effect
Scaling Functions Quantum Hall Effect
复制标题
缩放函数量子霍尔效应
DOI：
10.1143/jpsj.55.3199
复制
发表时间：
1986
影响因子：
1.7
通讯作者：
T. Ando
中科院分区：
文献类型：
--
作者：
T. Ando
用数值方法研究了磁场作用下二维系统中对角线和非对角线电导随系统尺寸的变化规律。对角线电导率由Thouless数得到，非对角线霍尔电导率由Kubo公式直接计算。结果表明，电导率不能被认为是独立的标度变量，而是随着系统规模的增大而随标度函数变化。标度函数与强磁场中的杂质浓度无关，但在弱磁场中受能级混合效应的影响较大。
System-size dependence of diagonal and off-diagonal conductivities is studied by a numerical method in two-dimensional systems in magnetic fields. The diagonal conductivity is obtained by the Thouless number and the off-diagonal Hall conductivity is calculated directly from the Kubo formula. It is demonstrated that the conductivities cannot be considered independent scaling variables but vary along a scaling function with the increasing system size. Scaling functions are independent of impurity concentrations in strong magnetic fields but strongly influenced by level-mixing effects in weaker magnetic fields.