Instituto de Física, Universidade Federal de Alagoas, Maceió-AL 57072-970, Brazil.
J Phys Condens Matter. 2011 May 4;23(17):175304. doi: 10.1088/0953-8984/23/17/175304. Epub 2011 Apr 12.
We study the wavepacket dynamics in a two-channel Anderson model with correlated diagonal disorder. To impose correlations in the disorder distribution we construct the on-site energy landscape following both symmetric and antisymmetric rules. Our numerical data show that symmetric cross-correlations have a small impact on the degree of localization of the one-particle eigenstates. In contrast, antisymmetric correlations lead to a reduction of the effective degree of disorder, thus resulting in a substantial increase of the wavepacket spread. A finite-size scaling analysis shows that the antisymmetric cross-correlations, in spite of weakening the localization, do not promote ballistic transport. The present results shed light on recent findings concerning an apparent delocalization transition in a correlated DNA-like ladder model.
我们研究了具有关联对角无序的双通道安德森模型中的波包动力学。为了在无序分布中引入相关性，我们按照对称和反对称规则构建了局域化能量景观。我们的数值数据表明，对称交叉相关对单粒子本征态的局域化程度影响很小。相比之下，反对称相关导致有效无序度的降低，从而导致波包扩展的大幅增加。有限尺寸标度分析表明，尽管反对称交叉相关削弱了局域化，但不会促进弹道输运。目前的结果为最近关于相关 DNA 梯模型中明显的非局域化转变的发现提供了线索。
