Extended States of a Layered Random System

Abstract

We investigate the localization properties of electronic wave functionsalong the normal of a layered system which is a random stacking of two typesof composite layers X and Y. It is shown that the energy spectrum ofthe system can have one or more channels of extended statesif i) X or Y has a repeated structure, ii) X and Y are symmetric, or iii) X and Y are the mirror images of each other. A similar effectis expected for the case of electromagnetic or acoustic wave.