Comparative numerical study of Anderson localization in disordered electron systems

TL;DR

This paper introduces a numerical scheme based on Chebyshev expansion to study the distribution of local density of states in disordered electron systems, effectively identifying the Anderson localization transition.

Contribution

The authors develop a Chebyshev-based numerical method to analyze LDOS distributions in large clusters, providing a new way to detect localization transitions in three-dimensional Anderson models.

Findings

LDOS distribution changes significantly at the localization transition

Typical density of states serves as an effective order parameter

Method reliably maps the phase diagram of the Anderson model

Abstract

Taking into account that a proper description of disordered systems should focus on distribution functions, the authors develop a powerful numerical scheme for the determination of the probability distribution of the local density of states (LDOS), which is based on a Chebyshev expansion with kernel polynomial refinement and allows the study of large finite clusters (up to $100^3$). For the three-dimensional Anderson model it is demonstrated that the distribution of the LDOS shows a significant change at the disorder induced delocalisation-localisation transition. Consequently, the so-called typical density of states, defined as the geometric mean of the LDOS, emerges as a natural order parameter. The calculation of the phase diagram of the Anderson model proves the efficiency and reliability of the proposed approach in comparison to other localisation criteria, which rely, e.g., on the decay of the wavefunction or the inverse participation number.