Anomalous diffusion, superlocalization and hopping conductivity on fractal media

A. Brooks Harris, A. Aharony

Research output: Contribution to journalArticlepeer-review

Abstract

We obtain simple, but rigorous bounds for impurity quantum states, for a tight-z binding model on random fractal structures. From these we conclude that a “typical„ state on a percolation cluster decays with Euclidean distance r as exp [- cra], with 1Š≤ŠaŠ≤Šςc, where rςcis the average chemical distance. Averaging over all random configurations yields regular exponential decay, aŠ=Š1. Our bounds indicate that the probability of a classical random walker to reach distance r at time t decays as exp [- (rd/w/t)α], tŠ< Šrdw, with 1/(dw - 1)Š≤ŠαŠ≤Šςc/(dw - ςc). For the fully averaged probability we expect αŠ=Š1/(dw - 1). The thermally activated hopping conductivity between impurities on a random structure with fractal dimensionality D is found to behave as exp [- (T0/T)β], with βŠ=Šςc/(D + ςc).

Original languageEnglish
Pages (from-to)1355-1360
Number of pages6
JournalEurophysics Letters
Volume4
Issue number12
DOIs
StatePublished - 15 Dec 1987

Fingerprint

Dive into the research topics of 'Anomalous diffusion, superlocalization and hopping conductivity on fractal media'. Together they form a unique fingerprint.

Cite this