Coherent Forward Scattering Peak Induced by Anderson Localization

TL;DR

This paper reports the discovery of a coherent forward scattering peak in wave momentum distribution at the onset of Anderson localization, supported by numerical simulations and diagrammatic analysis, indicating localization phenomena.

Contribution

It introduces the coherent forward scattering peak as a new interference feature associated with Anderson localization, complementing the known backscattering peak.

Findings

Identification of a forward scattering peak at localization onset

The peak emerges around the localization time

The peak grows on the scale of the Heisenberg time

Abstract

Numerical simulations show that, at the onset of Anderson localization, the momentum distribution of a coherent wave packet launched inside a random potential exhibits, in the forward direction, a novel interference peak that complements the coherent backscattering peak. An explanation of this phenomenon in terms of maximally crossed diagrams predicts that the signal emerges around the localization time and grows on the scale of the Heisenberg time associated with the localization volume. Together, coherent back and forward scattering provide evidence for the occurrence of Anderson localization.