2002/01/29 by A. Rodriguez, M. A. Martin-Delgado, J. Rodriguez-Laguna +4
Physics and Astronomy · #cond-mat.dis-nn
published as J. Lumin. vol 94-95 (2001) 359 · REVTeX 3, 3 Postscript figures
arxiv created 2002/01/29 · arxiv updated 2009/11/30
The standard one-parameter scaling theory predicts that all eigenstates in two-dimensional random lattices are weakly localized. We show that this claim fails in two-dimensional dipolar Frenkel exciton systems. The linear energy dispersion at the top of the exciton band, originating from the long-range inter-site coupling of dipolar nature, yields the same size-scaling law for the level spacing and the effective disorder seen by the exciton. This finally results in the delocalization of those eigenstates in the thermodynamic limit. Large scale numerical simulations allow us to perform a detailed multifractal analysis and to elucidate the nature of the excitonic eigenstates.