一维无序二元固体中电子局域性质的研究  

The localized properties of electronic states in one-dimensional disordered binary solid

作　　者：刘小良[1] 徐慧[1] 马松山[1] 宋招权[1] 

机构地区：[1]中南大学物理科学与技术学院,长沙410083

出　　处：《物理学报》2006年第6期2949-2954,共6页Acta Physica Sinica

基　　金：高等学校博士学科点专项科研基金(批准号:20020533001);湖南省自然科学基金(批准号:05JJ40135);中南大学文理基金(批准号:0601052)资助的课题

摘　　要：从单电子紧束缚模型的哈密顿量出发,格点能量随机取εA和εB,只计及格点之间的近程跳跃积分,建立了一维无序二元固体模型.利用负本征值理论及无限阶微扰理论,对系统电子的本征值和本征态进行了数值计算.结果表明与一定能量本征值对应的电子波函数只分布在系统的一定范围内,显示了其局域性.借助传输矩阵方法,计算出电子的局域长度,讨论了局域长度随本征能量和无序度的变化关系,并研究了计入不同范围跳跃积分下,局域长度的变化特征.Based on the tight-binding model of the single electron, the 1D model of disordered binary alloy is established, where two different diagonal energies εA and ε8 are assigned at random to each lattice site and only the short-range hopping integrals between the lattice sites are considered. Using the negative eigenvalue theory and the infinite order perturbation theory, we calculate numerically the eigenvalues and the eigenvectors of the electronic states. The results show that the electronic wave-functions only exist in some narrow region of the system and the localization properties are expected. Using the transfer matrix method, we calculate the localization lengths and discuss how they change with the eigen-energies and the degree of disorder and discuss some characteristics of the localization length with different hopping integral ranges.

关 键 词：无序 二元固体 电子态 局域长度 

分 类 号：O481[理学—固体物理]