# Intensity of waves inside a strongly disordered medium

## TL;DR

This study investigates wave intensity behavior inside strongly disordered media, revealing non-exponential decay, a universal intensity distribution at mobility edges, and challenging existing diffusion theories.

## Contribution

It provides new insights into wave intensity distribution in disordered media and critically evaluates current local diffusion theories of Anderson localization.

## Key findings

- Intensity remains roughly constant in the first half of the slab
- Sharp intensity drop occurs in the middle of the sample
- Universal intensity distribution observed at mobility edges

## Abstract

Anderson localization does not lead to an exponential decay of intensity of an incident wave with the depth inside a strongly disordered three-dimensional medium. Instead, the average intensity is roughly constant in the first half of a disordered slab, sharply drops in a narrow region in the middle of the sample, and then remains low in the second half of the sample. A universal, scale-free spatial distribution of average intensity is found at mobility edges where the intensity exhibits strong sample-to-sample fluctuations. Our numerical simulations allow us to discriminate between two competing local diffusion theories of Anderson localization and to pinpoint a deficiency of the self-consistent theory.