Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
J Phys Condens Matter. 2013 Oct 16;25(41):415501. doi: 10.1088/0953-8984/25/41/415501. Epub 2013 Sep 18.
We propose a scheme to generate metal-insulator transition in the random binary layer (RBL) model, which is constructed by randomly assigning two types of layers along the longitudinal direction. Based on a tight-binding Hamiltonian, the localization length is calculated for a variety of RBLs with different cross section geometries by using the transfer-matrix method. Both analytical and numerical results show that a band of extended states could appear in the quasi-one-dimensional RBLs and the systems behave as metals by properly tuning the model parameters, due to the existence of a completely ordered subband, leading to a metal-insulator transition in parameter space. Furthermore, the extended states are irrespective of the diagonal and off-diagonal disorder strengths. Our results can be generalized to two- and three-dimensional disordered systems with arbitrary layer structures, and may be realized in Bose-Einstein condensates.
我们提出了一种在随机二进制层（RBL）模型中产生金属-绝缘体转变的方案，该模型通过沿纵向随机分配两种类型的层来构建。基于紧束缚哈密顿量，我们使用转移矩阵方法计算了具有不同横截面几何形状的各种 RBL 的局域化长度。分析和数值结果均表明，在准一维 RBL 中可能会出现扩展态能带，并且通过适当调整模型参数，系统表现为金属，这是由于完全有序子带的存在，导致参数空间中的金属-绝缘体转变。此外，扩展态与对角和非对角无序强度无关。我们的结果可以推广到具有任意层结构的二维和三维无序系统，并可能在玻色-爱因斯坦凝聚体中实现。
