Electronic states in topologically disordered systems

TL;DR

This paper investigates the electronic energy states in topologically disordered systems modeled by Voronoi tessellations, revealing level repulsion similar to metallic Anderson models, thus enhancing understanding of disorder effects on energy spectra.

Contribution

It introduces a simple topological model for disordered networks and analyzes their energy spectra, highlighting the presence of level repulsion in such systems.

Findings

Energy-level-spacing distributions show level repulsion.

Disordered networks exhibit spectral properties akin to metallic regimes.

The model covers a wide range of natural disordered structures.

Abstract

Networks generated from Voronoi tessellations of space are prototypes for topologically disordered systems. In order to assess the effects of random coordination on the statistical properties of energy spectra, we analyze tight-binding models for planar topologically disordered systems. To this end, the networks are generated by a simple topological model covering a wide range of naturally observed random structures. We find that the energy-level-spacing distributions exhibit level repulsion, similar to the spacings in the energetically disordered Anderson model of localization in the metallic regime.