Extended acoustic modes in random systems with nmer short range correlations
Abstract
In this paper we study the propagation of acoustic waves in a onedimensional medium with a short range correlated elasticity distribution. In order to generate local correlations we consider a disordered binary distribution in which the effective elastic constants can take on only two values, η_{A} and η_{B}. We add an additional constraint that the η_{A} values appear only in finite segments of length n. This is a generalization of the wellknown randomdimer model. By using an analytical procedure we demonstrate that the system displays n1 resonances with frequencies ω_{r}. Furthermore, we apply a numerical transfer matrix formalism and a secondorder finitedifference method to study in detail the waves that propagate in the chain. Our results indicate that all the modes with ω≠ω_{r} decay and the medium transmits only the frequencies ω_{r}.
 Publication:

Journal of Physics Condensed Matter
 Pub Date:
 August 2011
 DOI:
 10.1088/09538984/23/34/345404
 Bibcode:
 2011JPCM...23H5404B