Berry effect in acoustical polarization transport in phononic crystals

TL;DR

This paper derives semiclassical equations for transverse acoustic waves in phononic crystals, revealing Berry effect phenomena like polarization rotation and Hall effects, applicable even in inhomogeneous media.

Contribution

It introduces a formalism that incorporates Berry effects into the wave dynamics of acoustical waves in phononic structures, extending to non-periodic media.

Findings

Berry effect terms cause polarization rotation

Hall effect depends on polarization

Formalism applies to inhomogeneous media

Abstract

We derive the semiclassical equations of motion of a transverse acoustical wave packet propagating in a phononic crystal subject to slowly varying perturbations. The formalism gives rise to Berry effect terms in the equations of motion, manifested as the Rytov polarization rotation law and the polarization-dependent Hall effect. We show that the formalism is also applicable to the case of non-periodic inhomogeneous media, yielding explicit expressions for the Berry effect terms.