准一维三平行链无序系统电子结构

利用负本征值理论计算方法,重点计算出准一维平行三链无序系统的电子态密度,对比研究了一维单链、准一维双链的情况.在对角无序、非对角无序条件下,具体探讨了电子结构、局域化形成、系统能量分布及维数效应等问题.研究表明,对角无序主要引起电子局域态的增多,非对角无序则使系统的能量分布范围发生变化;通过对一维到带状系统电子结构变化的研究,观察到在相同条件下,从一维到带状系统,电子态密度的峰值数目在增加,而电子态密度为零的能量区间减少,体现出电子能带结构的维数效应.

The Electronic Structure of Quasi-one-dimensional Disordered Systems with Three Parallel Chains

The densities of electronic states (DOS) of quasi-one-dimensional disordered systems with three parallel chains are computed with thirty thousand sites based on the negative eigenvalue theory. Compared with one-dimensional and quasi-one-dimensional disordered systems under conditions as diagonal disordered system and non-diagonal disordered system, the electronic structure, the localization of electrons, the distribution of the system energy and the dimensional effects are discussed. The results show that the diagonal disorder causes increasing of the number of localized electrons, and the non-diagonal disorder leads to changing of the distribution of the system energy. Comparing the electronic structure of one-dimensional system and quasi-one-dimensional system with three chains, we find that the peak number of the DOS increase, and the bandgap energy of zero DOS decreases.The dimensional effect of system under the same condition is shown.