Faraday Rotation in a Disordered Medium

TL;DR

This paper calculates the Faraday rotation angle in a 3D disordered medium, revealing its oscillatory nature and dependence on scattering properties, with implications for weak localization detection.

Contribution

It introduces a detailed calculation of Faraday rotation in disordered media, including effects of maximally crossed diagrams and their relation to weak localization.

Findings

Rotation angle oscillates with magnetic field and medium properties

Maximum rotation occurs at frequencies with minimal elastic mean free path

Backscattered light exhibits ellipticity as a precursor to weak localization

Abstract

The Faraday rotation angle is calculated in a diffusive regime in a three dimensional disordered slab. It is shown that it is an oscillating function of the magnetic field or the mediums internal properties, and is proportional to the ratio of the inelastic mean free path to the mean free path, that is to the average number of photon scatterings. The maximum rotation is achieved at frequencies when the photons elastic mean free path is minimal. We have obtained the rotation angle of polar backscattered light taking into account the maximally crossed diagrams. The latter leads to an ellipticity in the backscattered wave that can serve as precursor of weak localization.