ASA 125th Meeting Ottawa 1993 May

2pPA4. Intensity correlation and the approach to localization.

Azriel Z. Genack

Narciso Garcia

Jiang Hong Li

Dept. of Phys., Queens College of the City University of New York, Flushing, NY 11367

Because the conductance is the prime physical property of interest for electronics and also the universal scaling parameter of the electronic localization transition, considerable attention has focused upon the scaling of conductance. For classical waves, however, the localization transition can be followed not only by the scaling of the average of local or global quantities such as the intensity, transmission, or conductance, but also in a broad array of distributions and correlation functions, in which the proximity to the localization threshold is revealed, even in samples of a fixed size. Quantitative agreement is obtained between microwave measurements of spectral and spatial correlation in samples of randomly positioned polystyrene spheres and Langevin and macroscopic matrix calculations. The degree of correlation is shown to be the inverse of the dimensionless conductance even in the presence of absorption. The intensity distribution in this sample is also given in terms of the dimensionless conductance. Thus the approach to localization is revealed in the statistical character of propagation. The role of dielectric sphere resonances and the breakdown of the diffusion model is metallic mixtures will also be discussed. [Work supported by the NSF and the Petroleum Research Fund of the ACS.]