LEVEL STATISTICS FOR ELECTRONIC STATES IN A DISORDERED FRACTAL

Citation
Gn. Katomeris et Sn. Evangelou, LEVEL STATISTICS FOR ELECTRONIC STATES IN A DISORDERED FRACTAL, Journal of physics. A, mathematical and general, 29(10), 1996, pp. 2379-2387
Citations number
24
Categorie Soggetti
Physics
ISSN journal
03054470
Volume
29
Issue
10
Year of publication
1996
Pages
2379 - 2387
Database
ISI
SICI code
0305-4470(1996)29:10<2379:LSFESI>2.0.ZU;2-I
Abstract
We present results for the density of states and the statistics of the energy levels in a random tight binding matrix ensemble defined on a disordered two-dimensional Sierpinski gasket. In the absence of disord er the nearest level spacing distribution function P(S) is shown to fo llow the inverse power law P(S) proportional to S--D0-1, which defines the fractal dimension D-0 = 0.56 +/- 0.01 of the corresponding spectr um. In the random case P(S) approaches, instead, the Poisson law e(-S) , which is consistent with localization of the corresponding eigenstat es. In the presence of a random magnetic flux our results also scale t owards the Poisson statistics.