Decohering localized waves

TL;DR

This paper investigates how phase coherence affects wave localization, showing that decoherence from a dynamic environment causes spreading and destroys localization, with optimal phase fluctuations maximizing spreading due to a balance between diffusion and ballistic transport.

Contribution

It quantitatively demonstrates the critical role of phase coherence in wave localization and explores how decoherence impacts the transition from localized to diffusive spreading.

Findings

Decoherence destroys wave localization.

Maximal spreading occurs at optimal phase fluctuation conditions.

Decoherence induces diffusive spreading over localized states.

Abstract

In the absence of confinement localization of waves takes place due to randomness or nonlinearity and relies on their phase coherence. We quantitatively probe the sensitivity of localized wave packets to random phase fluctuations and confirm the necessity of phase coherence for localization. Decoherence resulting from a dynamical random environment leads to diffusive spreading and destroys linear and nonlinear localization. We find that maximal spreading is achieved for optimal phase fluctuation characteristics which is a consequence of the competition between diffusion due to decoherence and ballistic transport within the mean free path distance.