Microscopic Theory for Multiple Light Scattering in Magnetic Fields

TL;DR

This paper develops a microscopic theory for multiple light scattering in inhomogeneous media under magnetic fields, accounting for magneto-optical effects and their impact on light diffusion and polarization.

Contribution

It introduces a detailed microscopic model incorporating magneto-optical effects and anisotropy, advancing understanding of light transport in magnetized disordered media.

Findings

Magnetic fields induce anisotropy and birefringence affecting light diffusion.

The theory explains modifications in coherent backscattering due to magnetic effects.

Transport properties depend sensitively on scattering phase shifts.

Abstract

We present a microscopic theory for multiple light scattering occurring in inhomogeneous 3D media subject to an external magnetic field. Magneto-optical effects (the Faraday effect and the Cotton-Mouton effect) occur inside the small inhomogeneities. We thereby take into account the spatial anisotropy, time-reversal-symmetry breaking and birefringence caused by the magnetic field, and discuss the consequences for the diffusion tensor and the polarization characteristics of the diffuse light. We will frequently compare our findings to a similar phenomenon in dilute polyatomic gases: the Beenakker-Senftleben effect. Coherent Backscattering and the field-field correlator $\left< E_i({\bf B}) \bar{E}_j({\bf 0}) \right>$ are addressed, which have both been obtained experimentally by the group of Maret {\em etal.}. All modifications in transport theory due to the magnetic field exhibit a rather sensitive dependence on the scattering phase shift of the individual scatterers.