Universal scheme to generate metal-insulator transition in disordered systems

TL;DR

This paper introduces a universal scheme to induce metal-insulator transitions in disordered layered systems by tuning parameters, revealing extended states that are robust against disorder and applicable to higher dimensions and Bose-Einstein condensates.

Contribution

The study presents a novel method to generate metal-insulator transitions in disordered layered models, demonstrating the existence of extended states independent of disorder strength.

Findings

Extended states form a band in the RBL model.

Metal-insulator transition can be controlled via model parameters.

Extended states are robust against diagonal and off-diagonal disorder.

Abstract

We propose a scheme to generate metal-insulator transition in random binary layer (RBL) model, which is constructed by randomly assigning two types of layers. 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 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.