Berry Effect in Unmagnetized Inhomogeneous Cold Plasmas

TL;DR

This paper investigates how inhomogeneity in unmagnetized cold plasmas induces Berry effects, leading to polarization rotation and optical Hall effects, revealing new geometric phase phenomena in plasma wave propagation.

Contribution

It demonstrates the emergence of Berry phase and curvature effects in wave dynamics within unmagnetized inhomogeneous cold plasmas, a novel insight into plasma wave behavior.

Findings

Polarization plane rotates due to Berry phase (Rytov rotation)

Opposite deflections of circular polarizations cause optical Hall effect

Inhomogeneity induces gauge connection and Berry curvature in wave equations

Abstract

The propagation of electromagnetic waves in an unmagnetized weakly inhomogeneous cold plasma is examined. We show that the inhomogeneity induces a gauge connection term in wave equation, which gives rise to Berry effects in the dynamics of polarized rays in the post geometric optics approximation. The polarization plane of a plane polarized ray rotates as a result of the geometric Berry phase, which is the Rytov rotation. Also, the Berry curvature causes the optical Hall effect, according to which, rays of left/right circular polarization deflect oppositely to produce a spin current directed across the direction of propagation.