Magnetic-field-driven localization of light in a cold-atom gas

TL;DR

This paper reports a transition from extended to localized light modes in a cold-atom gas influenced by magnetic fields, density, and near-field interactions, resembling an Anderson transition.

Contribution

It reveals a magnetic-field-driven localization transition in cold atoms, highlighting the roles of near-field interactions and anisotropy, which are novel insights.

Findings

Transition from extended to localized light modes observed

Localization depends on atom density and magnetic field strength

Near-field interactions and anisotropy significantly influence localization

Abstract

We discover a transition from extended to localized quasi-modes for light in a gas of immobile two-level atoms in a magnetic field. The transition takes place either upon increasing the number density of atoms in a strong field or upon increasing the field at a high enough density. It has many characteristic features of a disorder-driven (Anderson) transition but is strongly influenced by near-field interactions between atoms and the anisotropy of the atomic medium induced by the magnetic field.