Number of propagating modes of a diffusive periodic waveguide in the semiclassical limit
Abstract
We study the number of propagating Bloch modes NB of an infinite periodic billiard chain. The asymptotic semiclassical behavior of this quantity depends on the phase-space dynamics of the unit cell, growing linearly with the wavenumber k in systems with a non-null measure of ballistic trajectories and going like ~ sqrt(k) in diffusive systems. We have calculated numerically NB for a waveguide with cosine-shaped walls exhibiting strongly diffusive dynamics. The semiclassical prediction for diffusive systems is verified to good accuracy and a connection between this result and the universality of the parametric variation of energy levels is presented.
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