Coherent Transport and Symmetry Breaking - Laser Dynamics of Constrained Granular Matter

TL;DR

This paper develops a diagrammatic transport theory for photon scattering in granular media, revealing how symmetry breaking due to dissipation influences coherence and lasing properties, with predictions testable in experiments.

Contribution

It introduces a parameter-free Vollhardt-Wölfle transport model that accounts for nonlinear effects and dissipation, linking symmetry breaking to laser mode characteristics in granular materials.

Findings

Symmetry breaking affects coherence and lasing thresholds.

Confined and extended modes correspond to unbroken and broken symmetry.

Predictions include emission profiles and coherence degrees testable experimentally.

Abstract

We present diagrammatic transport theory including self-consistent nonlinear enhancement and dissipation in the multiple scattering regime. Our model of Vollhardt-W\"olfle transport of photons is fit-parameter-free and raises the claim that the results hold up to the closest packed volume of randomly arranged ZnO Mie scatterers. We find that a symmetry breaking caused by dissipative effects of a lossy underlying substrate leads to qualitatively different physics of coherence and lasing in granular amplifying media. According to our results, confined and extended mode and their laser thresholds can be clearly attributed to unbroken and broken spatial symmetry. The diameters and emission profiles of random laser modes, as well as their thresholds and the positional-dependent degree of coherence can be checked experimentally.