Metalinsulator transition in chains with correlated disorder
Abstract
According to Bloch's theorem, electronic wavefunctions in perfectly ordered crystals are extended, which implies that the probability of finding an electron is the same over the entire crystal. Such extended states can lead to metallic behaviour. But when disorder is introduced in the crystal, electron states can become localized, and the system can undergo a metalinsulator transition (also known as an Anderson transition). Here we theoretically investigate the effect on the physical properties of the electron wavefunctions of introducing longrange correlations in the disorder in onedimensional binary solids, and find a correlationinduced metalinsulator transition. We perform numerical simulations using a onedimensional tightbinding model, and find a threshold value for the exponent characterizing the longrange correlations of the system. Above this threshold, and in the thermodynamic limit, the system behaves as a conductor within a broad energy band; below threshold, the system behaves as an insulator. We discuss the possible relevance of this result for electronic transport in DNA, which displays longrange correlations and has recently been reported to be a onedimensional disordered conductor.
 Publication:

Nature
 Pub Date:
 August 2002
 DOI:
 10.1038/nature00948
 Bibcode:
 2002Natur.418..955C